am 826c9f77: docs: fix broken link, reduce API info about backup and point to dev guide

Merge commit '826c9f7773188c2a7f48d5b2d1ae4612ec2bbb49' into froyo-plus-aosp

* commit '826c9f7773188c2a7f48d5b2d1ae4612ec2bbb49':
  docs: fix broken link, reduce API info about backup and point to dev guide