minor clarifications to README
minor clarifications to README

jaequery/cmd-key-happy,frobware/cmd-key-happy,frobware/cmd-key-happy,drewr/cmd-key-happy,drewr/cmd-key-happy,frobware/cmd-key-happy,scgilardi/cmd-key-happy,andymcd/cmd-key-happy,drewr/cmd-key-happy,jaequery/cmd-key-happy,frobware/cmd-key-happy,jaequery/cmd-key-happy,andymcd/cmd-key-happy,andymcd/cmd-key-happy,scgilardi/cmd-key-happy,andymcd/cmd-key-happy,frobware/cmd-key-happy,andymcd/cmd-key-happy,scgilardi/cmd-key-happy