Add blog post announcing validator for lessons
Typos and changes to section order.
Very small fix to @abought changes
Merge branch 'announce-validator' of github.com:r-gaia-cs/site into announce-validator
Blog post about accessibility guidelines
added missing step (#6); updated citation
Merge pull request #696 from dlebauer/patch-1

added missing step (#6); updated citation
Merge branch 'announce-validator'