added some documentation to the sample lua script
added some documentation to the sample lua script

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