Move some docs out of the README to make it less daunting
# WARNING: when these hooks run they will entirely destroy and rewrite# ~/.ssh/authorized_keys[hooks]changegroup.aaaab_update = hg update -C default > /dev/nullchangegroup.aaaac_purge = hg purge --all > /dev/nullchangegroup.refreshauth = python:mercurialserver.refreshauth.hook