* Convert some notes to warnings, move important text out of notes.
* Move enroll state documentation into a newly written section
(mostly copy-pasted from one of my recent emails to openstack-dev).
* Stop mentioning API version 1.11, as we already use it by default.
* Explain the 'baremetal configure boot' is no longer mandatory
starting with Newton.
* Write a section on automatically setting the root device hints.
* Move power state sync note to troubleshooting, as people are unlikely
to be interested in or even understand this part.
* Fix small mistakes.
Change-Id: I5f078bafd64d4fbcc5e83557f7761226cca93fd6
6b060fc283