Support for user-defined file extensions (e.g. .prg, .ch, .go)

[dszlage]

Hi 👋

Thank you for the awesome extension!

I'd like to request a feature that allows users to define additional file extensions that should be supported by the extension for Doxygen comment generation.

Use case: I'm working with a language like Harbour, Go which uses .go, .prg and .ch file extensions. Currently, the extension does not work in those files unless I use a workaround like changing "files.associations" in settings.json.

Feature request:
It would be great to have a setting like this:

json:
"doxdocgen.supportedFileExtensions": [".prg", ".ch"]

This would allow Doxygen-style comment generation in any user-defined file types, without needing to reassign language modes or rename files.

Thanks in advance!