Gemfile.lock is nolonger considered generated
Merge pull request #1733 from github/gemfile-lock-not-generated

Gemfile.lock is nolonger considered generated
fix vendor/cache
Mention that languages need to be quite popular

The precedent seems to be "hundreds of repos".
Merge pull request #1736 from github/aroben-patch-1

Mention that languages need to be quite popular