In Geany's `./template/files/` directory, I think it would be useful to be able to have subdirectories containing files that a user may want to group together and then such files would appear under a submenu of the "New" menu.
The use of this would be for people like me that have numerous templates and especially multiple related templates (like various C or Python templates). One may put their Python files (for example) in a directory called "Python" under `./template/files/` and then the "New" menu would have a "Python" submenu that lists all of the templates in that directory.