Add README.md with an initial help to work on command line para…

[koppor]

A question of how to develop a new command line option reached me. Therefore, I added some help. - I also made the links to the ADRs more prominent.

Using gradle's feature to pass command line arguments does not work in our settings. Current opinion: it is not about our custom groovy plugins, but because of something else. This is a TODO for a follow-up PR.

$  ./gradlew run --args="--help"
Starting a Gradle Daemon, 1 busy and 1 incompatible and 3 stopped Daemons could not be reused, use --status for details

> Configure project :
Found module name 'org.jabref'

> Task :compileJava
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

> Task :run
-Dfile.encoding=windows-1252
-Duser.country=DE
-Duser.language=de
-Duser.variant
org.jabref/org.jabref.JabRefLauncher
--help
-Dfile.encoding=windows-1252
-Duser.country=DE
-Duser.language=de
-Duser.variant
org.jabref/org.jabref.JabRefLauncher
--help
Importing in unknown format: -Dfile.encoding=windows-1252
Error opening file '-Dfile.encoding=windows-1252': Could not find a suitable import format.
Importing in unknown format: -Duser.country=DE
Error opening file '-Duser.country=DE': Could not find a suitable import format.
Importing in unknown format: -Duser.language=de
Error opening file '-Duser.language=de': Could not find a suitable import format.
Importing in unknown format: -Duser.variant
Error opening file '-Duser.variant': Could not find a suitable import format.
Importing in unknown format: org.jabref\org.jabref.JabRefLauncher
Error opening file 'org.jabref\org.jabref.JabRefLauncher': Could not find a suitable import format.
Importing in unknown format: --help
Error opening file '--help': Could not find a suitable import format.
15:20:57.752 [JavaFX Application Thread] INFO  org.jabref.gui.util.ThemeLoader - Enabling live reloading of C:\git-repositories\jab15:20:58.336 [JavaFX Application Thread] INFO  org.jabref.logic.importer.OpenDatabase - Opening: C:\jabref\demo-cleanup-using-doi.bib
15:20:58.375 [JavaFX Application Thread] INFO  org.jabref.logic.importer.OpenDatabase - Opening: C:\jabref\test-sync.bib

[tobiasdiez]

The additions look fine to me. But we should think about how we want to organize our development documentation, because otherwise we end up with some notes in the wiki and some in the docs folder, and some at still another location.

Personally, I would just create a new gitbook for the dev doc.