update README:
update README:

* fix typos
* update markdown formatting
* add Goals
* add TODO
* add @patcon to the contributors section
engineyard-cookbooks/percona,Sauraus/chef-percona,jharley/chef-percona,twistle/chef-percona,Sauraus/chef-percona,mevansam/chef-cookbook-percona,notion/chef-percona,twistle/chef-percona,bitpusher-real/chef-percona,archsaber/chef-percona,archsaber/chef-percona,phlipper/chef-percona,bitpusher-real/chef-percona,jharley/chef-percona,phlipper/chef-percona,notion/chef-percona