Adding tags to many examples (matplotlib#28569)

* Add example tags to the color examples directory

* Add example tags to the pie and polar examples

* Add tags to the subplots, axes, and figures examples

* Add tags to the lines, bars, and markers examples

* Add missing newline at end of joinstyle.py example

* Fix typos in tag directives.

* Fix rogue capitalization in tag of two_scales.py

* Fix typo

Co-authored-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>

---------

Co-authored-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>

Author: dihm

galleries/examples/color/color_by_yvalue.py

@@ -30,3 +30,10 @@
 #    in this example:
 #
 #    - `matplotlib.axes.Axes.plot` / `matplotlib.pyplot.plot`
+#
+# .. tags::
+#
+#    styling: color
+#    styling: conditional
+#    plot-type: line
+#    level: beginner

galleries/examples/color/color_cycle_default.py

@@ -50,3 +50,10 @@
 #    - `matplotlib.axes.Axes.axvline` / `matplotlib.pyplot.axvline`
 #    - `matplotlib.axes.Axes.set_facecolor`
 #    - `matplotlib.figure.Figure.suptitle`
+#
+# .. tags::
+#
+#    styling: color
+#    styling: colormap
+#    plot-type: line
+#    level: beginner

galleries/examples/color/color_demo.py

@@ -75,3 +75,9 @@
 #    - `matplotlib.axes.Axes.set_xlabel`
 #    - `matplotlib.axes.Axes.set_ylabel`
 #    - `matplotlib.axes.Axes.tick_params`
+#
+# .. tags::
+#
+#    styling: color
+#    plot-type: line
+#    level: beginner

galleries/examples/color/colorbar_basics.py

@@ -56,3 +56,10 @@
 #    - `matplotlib.figure.Figure.colorbar` / `matplotlib.pyplot.colorbar`
 #    - `matplotlib.colorbar.Colorbar.minorticks_on`
 #    - `matplotlib.colorbar.Colorbar.minorticks_off`
+#
+# .. tags::
+#
+#    component: colorbar
+#    styling: color
+#    plot-type: imshow
+#    level: beginner

galleries/examples/color/colormap_reference.py

@@ -95,3 +95,8 @@ def plot_color_gradients(cmap_category, cmap_list):
 #    - `matplotlib.axes.Axes.imshow`
 #    - `matplotlib.figure.Figure.text`
 #    - `matplotlib.axes.Axes.set_axis_off`
+#
+# .. tags::
+#
+#    styling: colormap
+#    purpose: reference

galleries/examples/color/custom_cmap.py

@@ -280,3 +280,9 @@
 #    - `matplotlib.cm`
 #    - `matplotlib.cm.ScalarMappable.set_cmap`
 #    - `matplotlib.cm.ColormapRegistry.register`
+#
+# .. tags::
+#
+#    styling: colormap
+#    plot-type: imshow
+#    level: intermediate

galleries/examples/color/individual_colors_from_cmap.py

@@ -63,3 +63,10 @@
 #
 #    - `matplotlib.colors.Colormap`
 #    - `matplotlib.colors.Colormap.resampled`
+#
+# .. tags::
+#
+#    component: colormap
+#    styling: color
+#    plot-type: line
+#    level: intermediate

galleries/examples/color/named_colors.py

@@ -121,3 +121,8 @@ def plot_colortable(colors, *, ncols=4, sort_colors=True):
 #    - `matplotlib.figure.Figure.subplots_adjust`
 #    - `matplotlib.axes.Axes.text`
 #    - `matplotlib.patches.Rectangle`
+#
+# .. tags::
+#
+#    styling: color
+#    purpose: reference

galleries/examples/color/set_alpha.py

@@ -51,3 +51,9 @@
 #
 #    - `matplotlib.axes.Axes.bar`
 #    - `matplotlib.pyplot.subplots`
+#
+# .. tags::
+#
+#    styling: color
+#    plot-type: bar
+#    level: beginner

galleries/examples/lines_bars_and_markers/bar_colors.py

@@ -24,3 +24,10 @@
 ax.legend(title='Fruit color')
 
 plt.show()
+
+# %%
+# .. tags::
+#
+#    styling: color
+#    plot-style: bar
+#    level: beginner