Expose and document ProjectSettings.get_global_class_list()

doc/classes/Variant.xml

@@ -38,7 +38,7 @@
 		        # To get the name of the underlying Object type, you need the `get_class()` method.
 		        print("foo is a(n) %s" % foo.get_class()) # inject the class name into a formatted string.
 		        # Note also that there is not yet any way to get a script's `class_name` string easily.
-		        # To fetch that value, you can parse the [code]res://.godot/global_script_class_cache.cfg[/code] file with the [ConfigFile] API.
+		        # To fetch that value, you can use [member ProjectSettings.get_global_class_list].
 		        # Open your project.godot file to see it up close.
 		[/gdscript]
 		[csharp]