Move the identity sources support matrix to the administrator guide and
clean up the remainder of the configuration page and the operator guide.
Change-Id: If6978121873b6b4a5438164f082f359688477298
This introduces the various ways you can configure keystone to
authenticate users, and provides a little compare/contrast to help
people understand how each solution behaves at a high level before
diving deeper.
This patch covers:
- SQL
- LDAP (considering that all write operations are deprecated)
- External authentication (REMOTE_USER)
- OAuth 1.0a
- OpenID Connect
- SAMLv2
Change-Id: I86dfbd2c1f7fed199c612dd1456358e559da3fad