docs: various updates and text fixes in HTML for MD conversion (#4837)

This PR contains various HTML updates and textual fixes in preparation for the planned markdown conversion (see also #4748).

For this PR, I have (briefly) reviewed all ~600 GRASS GIS manual pages by converting them to MD for a quality check, and then updated the original HTML files accordingly. Thus it is also a backport candidate for G84.

Changes in detail:

- adding missing intro sentences
- added module name in the first sentence where missing
- http -> https
- selected URL updates for broken URLs
- selected additions in "SEE ALSO" sections
- fix suboptimal HTML formatting (flags, special names, ...)
- add missing keywords on metapages
- remove leftover `Last changed: $Date$` entries from CVS/SVN days
- simplify selected `-<dl><dt>...` to `<ul><li>...` for improved MD conversion
- replaced `<tt>...</tt>` with `<code>...</code>` 

For an easier review, the changes have been submitted in separate commits:

- [x] **db**: 473b95b
- [x] **display**: fca42da
- [x] **doc**: e473bc8
- [x] **general**: 00930f5
- [x] **gui**: e9259cf
- [x] **imagery**: e700a7c, c888dba
- [x] **lib**: 6da27ca
- [x] **misc**: bfa7c0d
- [x] **raster**: 0c5ca83
- [x] **raster3d**: 0c44c95
- [x] **scripts**: e5bd683, 7b70b03
- [x] **temporal**: a173a8f
- [x] **vector**: b5167fa
- [x] **visualization**: 81e9756

Extra changes:
- [x] replaced `<tt>...</tt>` with `<code>...</code>` in 14841b2
- [x] dot product: replaced `.` with `&middot;` f8ea200
- [x] review by @echoix: 1645685 and 6fd0a66
- [x] `utils/g.html2man/htmltags.txt`: dropped outdated file (see instead `utils/g.html2man/ggroff.py`) in 92597b2

Co-authored-by: Edouard Choinière <27212526+echoix@users.noreply.github.com>

db/databaseintro.html

@@ -35,7 +35,7 @@ <h3>Attribute data import and export</h3>
 
 Further conversion tools:
 <ul>
-<li><a href="http://sourceforge.net/projects/mdbtools">MDB Tools</a>: Convert MS-Access data to SQL, DBF, etc.</li>
+<li><a href="https://github.com/mdbtools/mdbtools">MDB Tools</a>: Convert MS-Access data to SQL, DBF, etc.</li>
 <li><a href="https://grasswiki.osgeo.org/wiki/Openoffice.org_with_SQL_Databases">Using OpenOffice.org with SQL Databases</a></li>
 </ul>
 

db/db.connect/db.connect.html

@@ -9,7 +9,7 @@ <h2>DESCRIPTION</h2>
 
 <h2>NOTES</h2>
 
-Values are stored in the mapset's <tt>VAR</tt> file;
+Values are stored in the mapset's <code>VAR</code> file;
 the connection is not tested for validity.
 <p>The <b>-p</b> flag will display the current connection parameters.
 <p>The <b>-c</b> flag will silently check if the connection parameters have

db/db.execute/db.execute.html

@@ -76,7 +76,7 @@ <h2>EXAMPLES</h2>
 </pre></div>
 
 Update attribute with multiple SQL instructions in file
-(e.g., <tt>file.sql</tt>, instruction line must end with a semicolon):
+(e.g., <code>file.sql</code>, instruction line must end with a semicolon):
 <div class="code"><pre>
 UPDATE roads SET travelcost=5 WHERE cat=1;
 UPDATE roads SET travelcost=2 WHERE cat=2;

db/db.login/db.login.html

@@ -15,8 +15,8 @@ <h2>NOTE</h2>
 file in the user account, specifically
 
 <ul>
-<li> in the 'home' directory, i.e. <tt>$HOME/.grass8/dblogin</tt> (Unix-like systems)</li>
-<li> <tt>%APPDATA%\Roaming\GRASS8\dblogin</tt> (MS-Windows)</li>
+<li> in the 'home' directory, i.e. <code>$HOME/.grass8/dblogin</code> (Unix-like systems)</li>
+<li> <code>%APPDATA%\Roaming\GRASS8\dblogin</code> (MS-Windows)</li>
 </ul>
 
 Only the file owner can access this file.

db/drivers/ogr/README

@@ -5,4 +5,4 @@ SQL DB support via OGR
 
 -----------------------------------------------------
 General Documentation
-  http://www.remotesensing.org/gdal/ogr/ogr_sql.html
+  https://gdal.org/en/stable/user/ogr_sql_dialect.html

db/drivers/postgres/README

@@ -10,7 +10,7 @@ by G_warning().
 
 FIELD TYPES:
 Field type code may change. See for example
-http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/include/catalog/pg_type.h;hb=refs/heads/master
+https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/include/catalog/pg_type.h;hb=refs/heads/master
 
 Because of this, type codes must be read from server when database is opened.
 
@@ -19,7 +19,7 @@ Check also for PostgreSQL data types for defining them in GRASS:
 
 
 Supported types in ./globals.h:
-(See https://www.postgresql.org/docs/9.4/interactive/datatype.html)
+(See https://www.postgresql.org/docs/current/datatype.html)
 
 DB_C_TYPE_INT:
 bit, int2, smallint, int4, int, integer, int8, bigint, serial, oid

db/drivers/postgres/grass-pg.html

@@ -5,7 +5,7 @@
 
 <h2>Creating a PostgreSQL database</h2>
 
-A new database is created with <tt>createdb</tt>, see
+A new database is created with <code>createdb</code>, see
 the <a href="https://www.postgresql.org/docs/manuals/">PostgreSQL
 manual</a> for details.
 
@@ -76,7 +76,7 @@ <h2>Geometry import from PostgreSQL table into GRASS</h2>
 
 <h2>PostGIS: PostgreSQL with vector geometry</h2>
 
-<a href="http://postgis.refractions.net/">PostGIS</a>:
+<a href="https://postgis.net/">PostGIS</a>:
 adds geographic object support to PostgreSQL.
 
 <h3>Example: Import from PostGIS</h3>
@@ -114,15 +114,15 @@ <h3>Example: Import from PostGIS</h3>
 
 <h4>Geometry Converters</h4>
 <ul>
-<li><a href="http://postgis.refractions.net/download/">PostGIS with shp2pgsql</a>:<br>
- <tt>shp2pgsql -D lakespy2 lakespy2 test &gt; lakespy2.sql</tt>
+<li><a href="https://postgis.net/workshops/postgis-intro/loading_data.html#loading-with-shp2pgsql">PostGIS with shp2pgsql</a>:<br>
+ <code>shp2pgsql -D lakespy2 lakespy2 test &gt; lakespy2.sql</code>
 </li>
-<li><a href="http://e00pg.sourceforge.net/">e00pg</a>: E00 to PostGIS filter,
+<li><a href="https://e00pg.sourceforge.net/">e00pg</a>: E00 to PostGIS filter,
 see also <em><a href="v.in.e00.html">v.in.e00</a></em>.
 </li>
 <li>GDAL/OGR <a href="https://gdal.org/">ogrinfo and ogr2ogr</a>:
 GIS vector format converter and library, e.g. ArcInfo or SHAPE to PostGIS.<br>
-  <tt>ogr2ogr -f "PostgreSQL" shapefile ??</tt>
+  <code>ogr2ogr -f "PostgreSQL" shapefile ??</code>
 </li>
 </ul>
 
@@ -143,6 +143,6 @@ <h2>REFERENCES</h2>
 <ul>
 <li><a href="https://www.postgresql.org/">PostgreSQL web site</a></li>
 <li><a href="https://www.pgadmin.org/">pgAdmin graphical user interface</a></li>
-<li><a href="https://gdal.org/drv_pg.html">GDAL/OGR PostgreSQL
+<li><a href="https://gdal.org/en/stable/drivers/vector/pg.html">GDAL/OGR PostgreSQL
 driver documentation</a></li>
 </ul>

db/drivers/sqlite/grass-sqlite.html

@@ -34,7 +34,7 @@ <h2>Operators available in conditions</h2>
 
 <h2>Browsing table data in DB</h2>
 
-A convenient SQLite front-end is <a href="http://sqlitebrowser.sourceforge.net/">sqlitebrowser</a>.
+A convenient SQLite front-end is <a href="https://sqlitebrowser.org/">sqlitebrowser</a>.
 To open a DB file stored within the current mapset,
 the following way is suggested (corresponds to above database connection):
 
@@ -78,5 +78,5 @@ <h2>SEE ALSO</h2>
 <em>
   <a href="https://www.sqlite.org">SQLite web site</a>,
   <a href="https://www.sqlite.org/quickstart.html">SQLite manual</a>,
-  <a href="https://www.sqlite.org/cvstrac/wiki?p=ManagementTools">sqlite - Management Tools</a>
+  <a href="https://www2.sqlite.org/cvstrac/wiki?p=ManagementTools">sqlite - Management Tools</a>
 </em>

display/d.extract/d.extract.html

@@ -6,7 +6,7 @@ <h2>DESCRIPTION</h2>
 
 <h2>EXAMPLE</h2>
 
-<h3>Graphically extract roads from a roads map:</h3>
+<h3>Graphically extract roads from a roads map</h3>
 <div class="code"><pre>
 d.mon x0
 d.vect roads

display/d.graph/d.graph.html

@@ -132,10 +132,10 @@ <h2>COMMANDS</h2>
 <dt><a name="symbol"></a><b>symbol</b> <em>type size xper yper [line_color [fill_color]]</em></dt>
 <dd>A symbol is drawn at the given size on the display monitor. The
 <em>xper</em> and <em>yper</em> options define the center of the icon and
-are given as a percentage of the display frame (<tt>0,0</tt> is lower left).
-The symbol can be any of those stored in <tt>$GISBASE/etc/symbol/</tt>
+are given as a percentage of the display frame (<code>0,0</code> is lower left).
+The symbol can be any of those stored in <code>$GISBASE/etc/symbol/</code>
 (e.g. <i>basic/circle</i>) or stored in the user's mapset directory in the
-form <tt>$MAPSET/symbol/</tt><em>type/name</em>.
+form <code>$MAPSET/symbol/</code><em>type/name</em>.
 The colors may be either a standard color name, an R:G:B triplet,
 or "none". If using an R:G:B triplet, each color value can range from 0-255.
 If not specified the default <em>line_color</em> is black and the default

display/d.grid/d.grid.html

@@ -9,7 +9,7 @@ <h2>DESCRIPTION</h2>
 If the user provides a <b>-g</b> flag a geographic (projected) grid
 will be drawn. With the <b>-g</b> flag the <b>size</b>
 argument accepts both decimal degrees and colon separated
-ddd:mm:ss coordinates (eg. <tt>00:30:00</tt> for half of a degree).
+ddd:mm:ss coordinates (eg. <code>00:30:00</code> for half of a degree).
 A geographic grid cannot be drawn for a <em>latitude/longitude</em>
 or <em>XY</em> projection.
 

display/d.his/d.his.html

@@ -1,5 +1,9 @@
 <h2>DESCRIPTION</h2>
 
+<em>d.his</em> displays the result obtained by combining hue,
+intensity, and saturation (HIS) values from user-specified input
+raster map layers.
+<p>
 <em>HIS</em> stands for hue, intensity, and saturation.
 This program produces a raster map layer providing a
 visually pleasing combination of hue, intensity, and

display/d.labels/d.labels.html

@@ -7,7 +7,7 @@ <h2>DESCRIPTION</h2>
 the <em><a href="v.label.html">v.label</a></em> program or simply created
 by the user as an ASCII file (using a text editor) and placed in the
 appropriate directory under the user's current mapset and project
-(i.e. <tt>$MAPSET/paint/labels/</tt>).
+(i.e. <code>$MAPSET/paint/labels/</code>).
 
 <h2>NOTES</h2>
 

display/d.legend.vect/d.legend.vect.html

@@ -1,6 +1,6 @@
 <h2>DESCRIPTION</h2>
 
-Module <em>d.legend.vect</em> draws vector legend of currently displayed vector maps.
+<em>d.legend.vect</em> draws vector legend of currently displayed vector maps.
 <p>
 Parameter <b>at</b> defines the screen position of upper-left legend corner.
 Parameter <b>columns</b> defines the number of legend columns.

display/d.linegraph/d.linegraph.html

@@ -24,7 +24,7 @@ <h3>File inputs</h3>
 should) be only relative paths to these files. While this is not recommended
 for scripting, it can be advantageous when typing the paths
 manually. For example when all files are stored in the directory
-<tt>/home/john/data</tt>, the user can provide the following in the command
+<code>/home/john/data</code>, the user can provide the following in the command
 line:
 
 <div class="code"><pre>
@@ -145,7 +145,7 @@ <h2>EXAMPLE</h2>
 -->
 
 <p>
-The next command sequence creates a file <tt>plot.png</tt> in the current
+The next command sequence creates a file <code>plot.png</code> in the current
 directory which is the drawing made by <em>d.linegraph</em>.
 
 <div class="code"><pre>

display/d.mon/d.mon.html

@@ -52,8 +52,8 @@ <h3>Releasing (unselecting) a monitor</h3>
 <h2>NOTES</h2>
 
 <em>d.mon</em> is designed for interactive use. If non-interactive use
-is needed (e.g., in a script) set <tt>GRASS_RENDER_IMMEDIATE=png</tt>
-(or <tt>=cairo</tt>) and use the related environment
+is needed (e.g., in a script) set <code>GRASS_RENDER_IMMEDIATE=png</code>
+(or <code>=cairo</code>) and use the related environment
 <a href="variables.html">variables</a> to control output size etc.
 
 <h2>EXAMPLES</h2>
@@ -73,7 +73,7 @@ <h3>wx0 monitor</h3>
 <i>Figure: The initialization of display monitor wx0</i>
 </div>
 
-All subsequently displayed data will be rendered on monitor <tt>wx0</tt>.
+All subsequently displayed data will be rendered on monitor <code>wx0</code>.
 
 <div class="code"><pre>
 g.region raster=elevation -p
@@ -95,7 +95,7 @@ <h3>CAIRO file renderer monitor</h3>
 </pre></div>
 
 From this moment on all displayed data will be rendered into
-file <tt>output.pdf</tt>.
+file <code>output.pdf</code>.
 
 <h3>List running monitors</h3>
 

display/d.path/d.path.html

@@ -10,7 +10,7 @@ <h2>NOTE</h2>
 
 <!-- TODO: apparently d.path does not render into wxGUI? -->
 The user needs to display a vector map before using d.path. If no graphics monitor
-is open, a file <tt>map.png</tt> is generated in the current directory.
+is open, a file <code>map.png</code> is generated in the current directory.
 
 <p>
 The 'from' and 'to' points are entered by mouse into the map displayed in the GRASS monitor,

display/d.profile/d.profile.html

@@ -1,6 +1,6 @@
 <h2>DESCRIPTION</h2>
 
-This command displays the profile for a specified transect.
+<em>d.profile</em> displays the profile for a specified transect.
 
 <h2>SEE ALSO</h2>
 

display/d.rast.arrow/d.rast.arrow.html

@@ -17,7 +17,7 @@ <h2>DESCRIPTION</h2>
 of that category.
 Cells containing null data will be marked with an "X".
 You can disable drawing of null data and unknown aspect values by
-setting its color to "<tt>none</tt>".
+setting its color to "<code>none</code>".
 
 <p>When specifying the <em>magnitude_map</em> option, arrow lengths
 denoting magnitude will be extracted from the cell values of the specified
@@ -35,7 +35,7 @@ <h2>DESCRIPTION</h2>
 the raster map is relatively close in scale. You can use the <em>skip</em>
 option to draw arrows every n-th cell in both directions if you are working
 with relatively high resolutions. It may be useful to disable the grid in
-this case, which is accomplished by setting its color to "<tt>none</tt>".
+this case, which is accomplished by setting its color to "<code>none</code>".
 <p>For GRASS and Compass type aspect maps, the cell values of the aspect map
 will determine the corresponding direction in 360 degrees. ANSWERS type aspect
 maps will be plotted in multiples of 15 degrees counterclockwise from east, and

display/d.rast.num/d.rast.num.html

@@ -24,7 +24,8 @@ <h2>NOTES</h2>
 
 <h2>EXAMPLE</h2>
 
-A) Distance from the streams network (North Carolina sample dataset):
+Distance from the streams network (North Carolina sample dataset):
+
 <div class="code"><pre>
 g.region raster=streams_derived -p
 r.grow.distance input=streams_derived distance=dist_from_streams

display/d.rgb/d.rgb.html

@@ -1,5 +1,8 @@
 <h2>DESCRIPTION</h2>
 
+<em>d.rgb</em> displays three user-specified raster maps as red, green,
+and blue overlays in the active graphics frame.
+<p>
 <em>RGB</em> stands for <b>red</b>, <b>green</b>,
 and <b>blue</b>. <em>d.rgb</em> visually combines three raster maps to
 form a color image. For each map, the corresponding component from the

display/d.title/d.title.html

@@ -25,17 +25,18 @@ <h2>EXAMPLES</h2>
 For example, a user wishing to create a suitable TITLE for the
 Spearfish, SD <em>soils</em> map layer and to display this TITLE in the
 active display frame on the graphics monitor might type the following:
-<dl>
-<dd> <b>d.title map=</b><em>soils</em> <b>color=</b><em>red</em> <b>size=</b><em>5</em> <b>&gt; TITLE.file</b>
-<dd> <b><a href="d.text.html">d.text</a> &lt; TITLE.file</b>
-</dl>
+
+<div class="code"><pre>
+d.title map=soils color=red size=5 &gt; TITLE.file
+d.text &lt; TITLE.file
+</pre></div>
+
 Alternately, the user might pipe <em>d.title</em> output directly
 into <em><a href="d.text.html">d.text</a>:</em>
-<dl>
-<dd>
-<b>d.title map=</b><em>soils</em> <b>color=</b><em>red</em> <b>size=</b><em>5</em> |
-<a href="d.text.html">d.text</a>
-</dl>
+
+<div class="code"><pre>
+d.title map=soils color=red size=5 | d.text
+</pre></div>
 
 <p>A file created by <em>d.title</em> can be displayed
 with <em><a href="d.text.html">d.text</a></em>.
@@ -45,8 +46,10 @@ <h2>EXAMPLES</h2>
 
 <h2>SEE ALSO</h2>
 
-<em><a href="d.font.html">d.font</a></em><br>
-<em><a href="d.text.html">d.text</a></em><br>
+<em>
+<a href="d.font.html">d.font</a>,
+<a href="d.text.html">d.text</a>
+</em>
 
 <h2>AUTHOR</h2>
 

display/d.vect.thematic/d.vect.thematic.html

@@ -40,8 +40,8 @@ <h3>Thematic map with classes</h3>
 
 <h3>Thematic map with calculated class breaks</h3>
 
-The following example uses a calculated attribute (<tt>density =
-pop/area</tt>) and the standard deviation algorithm to calculate class
+The following example uses a calculated attribute (<code>density =
+pop/area</code>) and the standard deviation algorithm to calculate class
 breaks for 5 classes:
 
 <div class="code"><pre>

display/d.vect/d.vect.html

@@ -5,14 +5,14 @@ <h2>DESCRIPTION</h2>
 
 <h2>NOTES</h2>
 
-<em>d.vect</em> can simply be used typing <tt>d.vect
-map=vector_map</tt>. There are a large variety of optional parameters
+<em>d.vect</em> can simply be used typing <code>d.vect
+map=vector_map</code>. There are a large variety of optional parameters
 which allow the user to specify vector type, colors, data fields, SQL
 queries, label size and justification, etc.
 
 <p>When <em>d.vect</em> is used with <b>where</b> parameter on MS Windows
-Command Prompt, it is important to use <tt>&#710;</tt>
-carret symbol for escaping special characters <tt>&lt; &gt; ( ) &amp; &#124; , ; &quot;</tt>.
+Command Prompt, it is important to use <code>&#710;</code>
+carret symbol for escaping special characters <code>&lt; &gt; ( ) &amp; &#124; , ; &quot;</code>.
 <div class="code"><pre>
 d.vect map=vector_map where="cat &#710;&gt; 10 AND cat &#710;&lt; 20"
 </pre></div>
@@ -32,7 +32,7 @@ <h2>NOTES</h2>
 
 <p>Feature colors may be specified
 by <em><a href="v.colors.html">v.colors</a></em> in a form of color
-table or in an attribute table column containing <tt>RRR:GGG:BBB</tt>
+table or in an attribute table column containing <code>RRR:GGG:BBB</code>
 values.
 
 <p>A table for a vector map might look like this:

display/displaydrivers.html

@@ -3,7 +3,7 @@
 
 The current command line rendering mechanism is direct rendering into
 a file. The driver is selected by setting
-the <tt>GRASS_RENDER_IMMEDIATE</tt> variable or by
+the <code>GRASS_RENDER_IMMEDIATE</code> variable or by
 running <em><a href="d.mon.html">d.mon</a></em> module.
 
 <p>

doc/development/rfc/legal_aspects_of_code_contributions.md

@@ -66,4 +66,4 @@ source repository:
 Questions regarding GRASS GIS should be directed to the
 GRASS Development Team at the following address:
 
-Internet: <http://grass.osgeo.org/home/contact-us/>
+Internet: <https://grass.osgeo.org/support/community/>

doc/projectionintro.html

@@ -63,8 +63,8 @@ <h3>References</h3>
 <li> <a href="https://www.asprs.org/asprs-publications/grids-and-datums">ASPRS Grids and Datum</a></li>
 <li> <a href="http://geotiff.maptools.org/proj_list/">Projections Transform List</a> (PROJ)</li>
 <li> <a href="https://proj.org/operations/index.html">Coordinate operations</a> by PROJ (projections, conversions, transformations, pipeline operator)</li>
-<li> <a href="http://www.mapref.org">MapRef - The Collection of Map Projections and Reference Systems for Europe</a></li>
-<li> <a href="http://crs.bkg.bund.de/crs-eu/">Information and Service System for European Coordinate Reference Systems - CRS</a></li>
+<li> <a href="https://mapref.org">MapRef - The Collection of Map Projections and Reference Systems for Europe</a></li>
+<li> <a href="https://www.crs-geo.eu/">Information and Service System for European Coordinate Reference Systems - CRS</a></li>
 </ul>
 
 <h3>See also</h3>

general/g.filename/g.filename.html

@@ -6,7 +6,7 @@ <h2>DESCRIPTION</h2>
 <p>The list of element names to search for is not fixed; any subdirectory of the
 mapset directory is a valid element name.
 <p>However, the user can find the list of standard GRASS GIS element names in
-the file <tt>$GISBASE/etc/element_list</tt>. This is the file which
+the file <code>$GISBASE/etc/element_list</code>. This is the file which
 g.remove/g.rename/g.copy use to determine which files need to be
 deleted/renamed/copied for a given entity type.