Update docs for pach.
Update docs for pach.

klucar/pachyderm,sambooo/pachyderm,klucar/pachyderm,sambooo/pachyderm,alexdebrie/pachyderm,klucar/pachyderm,sambooo/pachyderm,ShengjieLuo/pachyderm,alexdebrie/pachyderm,alexdebrie/pachyderm,ShengjieLuo/pachyderm,ShengjieLuo/pachyderm