Add h* font size variables and margin
Some small README updates
Merge pull request #76 from thoughtbot/kf-small-readme-updates

Some small README updates
Merge pull request #60 from thoughtbot/wm-headersize

Add h* font size variables and margin
Make readme more clear and fix typos
Merge pull request #79 from thoughtbot/tg-fix-readme-typos

Make readme more clear and fix typos