Godot 4 script templates fix

[DaniChristiaans]

RESOLVES ISSUE #82

Update script templates with Godot 4 syntax and folder hierarchy:

• Place script templates in a Node subfolder, which is required for Godot 4 to detect the script templates
• Replace % with _ (example: %BASE% becomes BASE, %TS% becomes TS), according to new Godot 4 syntax for script templates

[manuq]

@daneehAI oh I didn't notice your PR so I the same thing in parallel https://github.com/ephread/inkgd/pull/97

However, note that this is not enough. In my PR I have also changed the plugin to install the script templates correctly: https://github.com/ephread/inkgd/pull/97/files#diff-e377186e5b5fa5981f46565ec79c2653e506b4de56e478273341c81f207f3d96