Update Gems
Consolidate headers and caption tutorial to simple tables

+ change in CSS
Renaming/Reordering Tutorial Examples
Transition to have the markdown extension last

This will make editors happier :-)
Add classes to color source code in body text
Fix unnecessary ps around HTML elements
Changed tips order
Cleanup table summary page
Added example headings
Cleanup
Added section about splitting up multi-level tables
Notes in the new format
First shot at redoing the tables concepts page
Merge pull request #24 from w3c/dev

Rearrangement of the table tutorial