WIP: Add option for CUSTOM language definitions

[drkameleon]

As per https://github.com/alstr/todo-to-issue-action/issues/104

P.S. I'm not sure if it's exactly what you suggested, plus - as I've already mentioned - I'm not a Python guy at all, so, it may have ended up looking like Swahili lol. If it doesn't, then I would love to hear your comments.

[alstr]

I've updated the Python a little and it seems to append the custom languages fine. I've not been able to test it with any actual custom file yet though. Don't know if you want to try it out? You'll just have to make a couple of changes so it doesn't run the prebuilt action image, described here: https://github.com/alstr/todo-to-issue-action/issues/101. Thanks!

[drkameleon]

I've updated the Python a little and it seems to append the custom languages fine. I've not been able to test it with any actual custom file yet though. Don't know if you want to try it out? You'll just have to make a couple of changes so it doesn't run the prebuilt action image, described here: #101. Thanks!

I'll try to test it myself and I will let you know how it goes! 😉

Thanks!

[alstr]

No problem, thanks! We'll need to add the input to action.yml as well.

[alstr]

Closing due to inactivity but feel free to reopen.