Fix GDScript example formating

First 3 lines of actual code appeared in the tab title instead of in the code block.

tutorials/plugins/editor/inspector_plugins.rst

@@ -43,6 +43,7 @@ you should remove the instance you have added by calling
 
 .. tabs::
   .. code-tab:: gdscript GDScript
+  
     # plugin.gd
     tool
     extends EditorPlugin