Add xccheckout files to gitignore
Add xccheckout files to gitignore

fhchina/liftoff,IntrepidPursuits/homebrew-liftoff,makingspace/liftoff,makingspace/liftoff,liftoffcli/liftoff,liftoffcli/liftoff,fhchina/liftoff,fousa/liftoff,fousa/liftoff,IntrepidPursuits/homebrew-liftoff,IntrepidPursuits/homebrew-liftoff,fhchina/liftoff,makingspace/liftoff,fousa/liftoff,liftoffcli/liftoff