Removes inline styles (DEVELOPER-832)

This removes all inline styles, I've replaced them with classes where I
could. The one place this hasn't worked out is in the microsite hero
image. We'll need to figure that one out.

Adding in the default microsite hero banner.
Add image instructions to CONTRIBUTING.md
Merge pull request #638 from pmuir/image_contributions

Add image instructions to CONTRIBUTING.md
Merge pull request #613 from LightGuard/DEVELOPER-832

Removes inline styles (DEVELOPER-832)
Update cdn.yml
DEVELOPER-1083 Requesting home page promo to support JBoss Fuse for xPaaS launch
DEVELOPER-1075 Updates to jboss.org/product/fuse page to support xPaaS launch
DEVELOPER-1076 Updates to jboss.org/product/amq page to support xPaaS launch