Clarify some of the git-http-backend documentation, particularly:
* In the Description, state that smart/dumb HTTP fetch and smart HTTP
push are supported, state that authenticated clients allow push, and
remove the note that this is only suited for read-only updates.
* At the start of Examples, state explicitly what URL is mapping to what
location on disk.
Signed-off-by: Mark Lodato <lodatom@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>