Merge branch 'master' into dev

* master:
  Adding local W3C & WAI logo copies, also…
  cleanup
  Rename Summarize Tables to Table Summary again
  Cleanup tables concepts page
  Fragmention styling
  s/jQuery/Vanilla JS
  Add fragmention support
  Making the page protocol insensitive
  Some more cleanup
  Fork & edit this file on github
  Add  approaches to structured table tutorial
  clean up index page
  clean up tables tips and faqs
  Add better links from fullcode example
  Change 'Image' to 'Images'
  Update informative.html.erb.md
  Update informative.html.erb.md
  Add note about MarkDown preview
Forms Concepts page – first go at cleanup
Labels page cleanup
Clean up labels

Including adding a section about implicit labels
Add Editor’s notes
Split up structure.html into groups.html & complex.html
Different color for Editor’s note
Start to edit forms/groups.html
Merge branch 'master' into dev

* master:
  Final cleanup of the tables tutorial
  Font size of the <code> elements
Rewrite page title
Merge branch 'dev'

* dev:
  Rewrite page title
  Start to edit forms/groups.html
  Different color for Editor’s note
  Split up structure.html into groups.html & complex.html
  Add Editor’s notes
  Clean up labels
  Labels page cleanup
  Forms Concepts page – first go at cleanup

Conflicts:
	source/layouts/_header.erb