docs(bare-metal): filled in bare metal section in provision doc

We need a docs.deis.io anchor for bare metal to reference from deis.io.
Merge pull request #982 from deis/update-provision-doc

docs(bare-metal): filled in bare metal section in provision doc
docs(*): update docs for local3.deisapp.com, local5.deisapp.com

We've created the convenience records for local3.deisapp.com and
local5.deisapp.com, so local clusters no longer have to manage
DNS whatsoever.

closes #747