add note about EditorScript only runnable from internal script editor

Author: AdriaandeJongh

tutorials/plugins/running_code_in_the_editor.rst

@@ -292,14 +292,14 @@ Running one-off scripts using EditorScript
 Sometimes, you need to run code just one time to automate a certain task that is
 not available in the editor out of the box. Some examples might be:
 
-- Use as a playground for GDScript scripting without having to run a project.
+- Use as a playground for GDScript or C# scripting without having to run a project.
   ``print()`` output is displayed in the editor Output panel.
 - Scale all light nodes in the currently edited scene, as you noticed your level
   ends up looking too dark or too bright after placing lights where desired.
 - Replace nodes that were copy-pasted with scene instances to make them easier
   to modify later.
 
-This is available in Godot by extending :ref:`class_EditorScript` in a GDScript.
+This is available in Godot by extending :ref:`class_EditorScript` in a script.
 This provides a way to run individual scripts in the editor without having to
 create an editor plugin.
 
@@ -333,6 +333,11 @@ currently focused on the script editor.
 
 Scripts that extend EditorScript must be ``@tool`` scripts to function.
 
+.. note::
+
+    If you are using an external editor, open the script inside the Godot
+    script editor so you can execute the function.
+
 .. warning::
 
     EditorScripts have no undo/redo functionality, so **make sure to save your