Expand README.
Expand README.

henrylee2cn/pachyderm,pachyderm/pfs,pachyderm/pfs,klucar/pachyderm,sambooo/pachyderm,sambooo/pachyderm,kunthar/pachyderm,sambooo/pachyderm,kunthar/pachyderm,alexdebrie/pachyderm,ShengjieLuo/pachyderm,alexdebrie/pachyderm,klucar/pachyderm,phacops/pachyderm,klucar/pachyderm,wideioltd/pachyderm,alexdebrie/pachyderm,ShengjieLuo/pachyderm,wideioltd/pachyderm,pachyderm/pfs,henrylee2cn/pachyderm,ShengjieLuo/pachyderm,phacops/pachyderm