Update the 10.1-RELEASE schedule page to reflect that the
releng/10.1 branch has been created, and the 10.1-RC1 builds
have started.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Add releng/10.1 to the branch list.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Add the errata, hardware, readme, and relnotes pages for
the 10.1-RELEASE, generated after branching releng/10.1.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation