Update README.

Removed a few sections of the README that were either out of date or
irrelevant.

Change-Id: I32cc9190558806cefe58421abbe48918c7310779
Re-added cell carrier header.

Change-Id: I6bb92c42b8f1688504f99ffd8851b69c94f42d65
Merge "Re-added cell carrier header."
Localisation updates from https://translatewiki.net.

Change-Id: Iab3c66845592b767fba8c1193d14749850939c22
Change "Credits" to "About".

Includes version info and other items from Android version.

Updated doc type index.html to strict.

Updated doc types to not include outdated version info.

Re-added "repositories" section to About page.

Change-Id: I9914dd0c56af25d7ecf9cbeb25245b939540a0a4