This is a follow up to Ie039322660fd0e2e0403843448379b78114c425b.
A few things are changed here:
* The note about using file injection is removed. File injection
was deprecated in the API in Queens and not something that we
really want users using.
* Mention that creating a flavor is typically admin-only.
* Link to the BDM docs for more details about BDM parameter values.
* Update the manage-ip-address docs to make the examples rely on
using the networking resource CLIs rather than any proxy APIs
that were available in nova.
Change-Id: Ifa2e2bbb4c5f51f13d1a5832bd7dbf9f690fcad7