Import coalaCSS coala.css as an asset

the coast project now has a coala.css , and others use it dynamically.

It is actually nicer to have this file in the local repo , as static site generators often process the style files.

Add coalaCSS as an upstream for this repo, so we can be 100% certain this repo version is kept up to date.

Then we can add moban to coast repo, to prevent anyone editing that .css file.