support for other languages

It would be nice if the user could decide which language he prefers (just like the original patternlab). Do you agree?

I quickly added sass-support by adding a `elseif`, but this was just my fist idea. 

In the end pattern.php should be more or less independend from languages/suffixes. Important for now: less, scss, sass and css, but who knows what will be in the future. So maybe it needs something like a config-file or some kind of auto-detection. But you have probably better / more kirbyish ideas about that.