Move selector to its own line
Minor tweats to initial Update content for Pure 0.2.0
Add info about improved developer workflow to 0.2.0 update post
Change font-size of h3s and h4s

I noticed that our main paragraph font-size is 18px, so I bumped up the
heading sizes so that h4s are as large (18px) as the paragraph text.
add CONTRIBUTING.md paragraph