Add LESS linter pre-commit hook

[Friend-LGA]

Why did you forget about LESS?

Here documentation about LESS lint

[jawshooah]

If it's not here, it's only because nobody has submitted a PR to add it yet. You're welcome to take a crack at it and submit a PR yourself 😄

[Ruffeng]

Would you go for a Less Linter? Or do you think is good to add stylelint, which can cover different formats?

[Ruffeng]

#521
@brianbancroft already did a PR

[leblangi]

Stylelint is in the list and support less. I think we can close this issue :)