fix(docs): document the new flow events
fix(docs): document the new flow events

r=vbudhram
mozilla/fxa-auth-server,eoger/fxa-auth-server,eoger/fxa-auth-server,eoger/fxa-auth-server,shane-tomlinson/fxa-auth-server,shane-tomlinson/fxa-auth-server,mozilla/fxa-auth-server,shane-tomlinson/fxa-auth-server,mozilla/fxa-auth-server,eoger/fxa-auth-server,mozilla/fxa-auth-server,shane-tomlinson/fxa-auth-server