CSS Setup

[ariporad]

Hi!

This theme looks super cool, so I'm trying to adapt it for my needs. However, I'm running into some problems with the css.

It looks like some of the css is in _sass/, while some is in less/, and I'm not sure what the difference is. I'm also not really sure where Gulp fits in.

Thanks so much for your help!

[mayppong]

If this could be clarify, I'm happy to submit a PR to update the build process for it as well.