[Feature] Show full language name + extension

[Chris2011]

If you have a look into my old plugin: https://github.com/Chris2011/NbScratchFile I show also the language name, which is pretty handy, beacuse I can type rust or kotlin and find what I need. Unfortunately I have a static list for all of those files that I think are supported. It would be good that we can have those names too to recognice the file better.

[github-actions]

Thanks for reporting this issue, we will take a look on ASAP