doc: Make all module docs self-contained

modules/gdscript/config.py

@@ -1,8 +1,15 @@
-
-
 def can_build(platform):
     return True
 
-
 def configure(env):
     pass
+
+def get_doc_classes():
+    return [
+        "GDFunctionState",
+        "GDNativeClass",
+        "GDScript",
+    ]
+
+def get_doc_path():
+    return "doc_classes"