Minor documentation improvements
Minor documentation improvements

Summary: Minor tidying of documentation and adding some groups.

Test Plan: Eyeball it.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D13135

sneakpeeq/arcanist,uber/arcanist,phacility/arcanist,jra3/arcanist,kevinseelbach/arcanist,folsom-labs/arcanist,phacility/arcanist,eSpark/arcanist,Khan/arcanist,wxstars/arcanist,codelabs-ch/arcanist,KieranHayes/arcanist,coursera/arcanist,haskell-infra/arcanist,wxstars/arcanist,eSpark/arcanist,aik099/arcanist,kevinseelbach/arcanist,haskell-infra/arcanist,r4nt/arcanist,r4nt/arcanist,wharris/arcanist,wikimedia/phabricator-arcanist,codelabs-ch/arcanist,alexmv/arcanist,PageUpPeopleOrg/arcanist-patches,memsql/arcanist,fivestars/arcanist,wxstars/arcanist,uber/arcanist,calblueprint/arcanist,r4nt/arcanist,sneakpeeq/arcanist,coursera/arcanist,wharris/arcanist,haskell-infra/arcanist,zhihu/arcanist,eSpark/arcanist,wikimedia/phabricator-arcanist,phacility/arcanist,jra3/arcanist,folsom-labs/arcanist,memsql/arcanist,wxstars/arcanist,hach-que/arcanist,phacility/arcanist,wikimedia/phabricator-arcanist,Symplicity/arcanist,jra3/arcanist,chundongwang/arcanist,Symplicity/arcanist,fivestars/arcanist,calblueprint/arcanist,alexmv/arcanist,hach-que/arcanist,wharris/arcanist,aik099/arcanist,wikimedia/phabricator-arcanist,calblueprint/arcanist,folsom-labs/arcanist,PageUpPeopleOrg/arcanist-patches,fivestars/arcanist,kevinseelbach/arcanist,KieranHayes/arcanist,calblueprint/arcanist,hach-que/arcanist,uber/arcanist,eSpark/arcanist,alexmv/arcanist,Khan/arcanist,KieranHayes/arcanist,PageUpPeopleOrg/arcanist-patches,zhihu/arcanist,Khan/arcanist,phacility/arcanist,alexmv/arcanist,KieranHayes/arcanist,zhihu/arcanist,sneakpeeq/arcanist,memsql/arcanist,wharris/arcanist,r4nt/arcanist,codelabs-ch/arcanist,chundongwang/arcanist,folsom-labs/arcanist,memsql/arcanist,PageUpPeopleOrg/arcanist-patches,Symplicity/arcanist,chundongwang/arcanist,haskell-infra/arcanist,chundongwang/arcanist,aik099/arcanist,sneakpeeq/arcanist,coursera/arcanist,zhihu/arcanist,Khan/arcanist,uber/arcanist,aik099/arcanist,Symplicity/arcanist,kevinseelbach/arcanist,codelabs-ch/arcanist,codelabs-ch/arcanist,coursera/arcanist,fivestars/arcanist,jra3/arcanist,hach-que/arcanist