Add support for lexc in GH Linguist

[snomos]

Cf https://github.com/github/linguist/blob/master/CONTRIBUTING.md

There is already one for VSCode here: https://github.com/eddieantonio/vscode-lexc

There are more than 200 repos with lexc files, according to this search:

https://github.com/search?p=1&q=extension%3Alexc+NOT+nothack&type=Code (4930 hits).

Benefits:

• our actual code would count in the code statistics, not just Makefiles etc
• syntax highlighting in Markdown files and other GH places
• more visibility for our work 👍

WDYT @flammie @albbas @Trondtr @ftyers

[flammie]

sounds like a good idea, I know apertium folks have doen some work with github linguist but I got the impression the syntax for the thing was not very nice to work with so I haven't researched further. Is this vscode grammar the same as the textmate they are expectig?

[snomos]

I don’t know, but it should in any case be a good start.

[mr-martian]

My understanding is that textmate grammars are in the process of being replaced by tree-sitter grammars, though there isn't yet an established way to submit one of the latter, though such a grammar now exists: https://github.com/apertium/tree-sitter-apertium, which might be a reason to wait a bit and see if they provide a way to submit that.