Add descriptions to all projects with README files

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

loading/autoload/project.godot

@@ -16,6 +16,7 @@ _global_script_class_icons={
 [application]
 
 config/name="Autoload (Singletons)"
+config/description="This demo shows how to use autoloads to change between scenes."
 run/main_scene="res://scene_a.tscn"
 
 [autoload]

loading/background_load/project.godot

@@ -16,6 +16,8 @@ _global_script_class_icons={
 [application]
 
 config/name="Background Thread Loading Demo"
+config/description="This is a demo showing how to use the load_interactive() method of
+ResourceLoader to load large scenes in the background with a progress bar."
 run/main_scene="res://paintings.tscn"
 
 [autoload]

loading/multiple_threads_loading/README.md

@@ -1,6 +1,7 @@
 # Multiple-threads loading demo
 
-This demo shows how you can organize background loading using multiple threads.
+This demo shows how you can organize
+background loading using multiple threads.
 
 Language: GDScript
 

loading/multiple_threads_loading/project.godot

@@ -16,6 +16,8 @@ _global_script_class_icons={
 [application]
 
 config/name="Multiple threads loading"
+config/description="This demo shows how you can organize
+background loading using multiple threads."
 run/main_scene="res://preload.tscn"
 config/icon="res://icon.png"
 

loading/scene_changer/project.godot

@@ -16,6 +16,7 @@ _global_script_class_icons={
 [application]
 
 config/name="Scene Changer"
+config/description="This uses functions in SceneTree to switch between two scenes."
 run/main_scene="res://scene_a.tscn"
 
 [debug]

loading/threads/project.godot

@@ -16,6 +16,7 @@ _global_script_class_icons={
 [application]
 
 config/name="Loading in a Thread"
+config/description="An example using a thread to load an image."
 run/main_scene="res://thread.tscn"
 
 [display]