Support for LESS

[ciembor]

Hey, I don't know, maybe not many people use LESS anymore over SCSS. I have 12 years old project with LESS (now inside Vue components), it would be useful to add linter for it and I think this is the best place :).

[ota-meshi]

Thank you for posting this issue.

I don't use LESS so I can't create that 😓
Could you consider sending a pull request to this repository?