Create re-usable templates for events and news

As discussed with @autumnfound, we should include a default mustache template for events and news.

I am thinking we can use some of the work we did for openhwgroup: https://github.com/openhwgroup/openhwgroup.org/blob/master/js/templates/event-list-format.mustache https://github.com/openhwgroup/openhwgroup.org/blob/master/js/templates/news-no-mh.mustache

and the less file from https://github.com/openhwgroup/openhwgroup.org/commit/d6789163b91011ac0fc2d7899384b3a1c1f2056b