More changes to customize ads
Fixes #630 - clarifies adding a <span>
Adding sample for customize
Removing unnecessary JS file.
Improvements to customize ads doc.
Content tweaks
Updating URLs pointing to AdSense help
More changes to customize ads. We might just be ready to launch.
Small nits to get ready for publishing.
Rename ad-monetization to ads
Removing from collection for point release.
Changing section name to ads
Removing picturefill lib from Git, see issues #636
Fixes #638
Fixes #636
Actioning Matt's review comments
Small nit fixed.
Fixes #644 - better describes example shown
Fixes 640 - addresses placeholders disappearing
Fixes #646 - updates contribution guidelines.