Add descriptions to all projects with README files

These show up in the project manager when hovering over projects.

gui/drag_and_drop/project.godot

@@ -16,6 +16,10 @@ _global_script_class_icons={
 [application]
 
 config/name="Drag & Drop (GUI)"
+config/description="A demo showcasing drag and drop functionality.
+
+- Drag and drop the color buttons to copy their colors over.
+- Click on the buttons to manually adjust their color."
 run/main_scene="res://drag_and_drop.tscn"
 config/icon="res://icon.png"
 

gui/input_mapping/project.godot

@@ -16,6 +16,11 @@ _global_script_class_icons={
 [application]
 
 config/name="Input Mapping GUI"
+config/description="A demo showing how to build an input key remapping screen.
+
+- Click the buttons to change the bound keys.
+- Persists the keys to disk, so they are preserved
+  after the project is restarted."
 run/main_scene="res://InputRemapMenu.tscn"
 config/icon="res://icon.png"
 

gui/rich_text_bbcode/project.godot

@@ -16,6 +16,7 @@ _global_script_class_icons={
 [application]
 
 config/name="Rich Text Label with BBCode"
+config/description="A demo showcasing the support for rich text and BBCode via RichTextLabel."
 run/main_scene="res://rich_text_bbcode.tscn"
 config/icon="res://icon.png"
 

gui/translation/README.md

@@ -1,6 +1,7 @@
 # GUI Translation Demo
 
-A demo showing how Godot seamlessly enables the use of localized resources and texts.
+A demo showing how Godot seamlessly enables
+the use of localized resources and texts.
 
 Language: GDScript
 

gui/translation/project.godot

@@ -16,6 +16,8 @@ _global_script_class_icons={
 [application]
 
 config/name="Translation Demo"
+config/description="A demo showing how Godot seamlessly enables
+the use of localized resources and texts."
 run/main_scene="res://translation_demo.tscn"
 config/icon="res://icon.png"