New Feat: Allow Theme Gen Sync Plugin to work with external editors

[RickyRicardo1117]

New Feature Request
Setup the Theme Gen Sync Plugin to work with external editors.
Or add in something, preferably magic, to get this working without having to use the internal editor.

Right now the workflow with an external editor is:

1. Turn off 'external editor' option.
2. Open the file in godot.
3. Turn back on the external editor option.
4. Use the internal editor to run the script whenever finished.

Would love to use this but right now, this just isn't really feasible for external editor users.