correct gcfg command example to cue command
Closes #37
https://github.com/cuelang/cue/pull/37
GitOrigin-RevId: f5afe759169f40faa128b07b50bfd043e9dd935f
Change-Id: Id6c965d49087cfff25565fa0ccdba854096ec1a7
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/1860
Reviewed-by: Marcel van Lohuizen <mpvl@google.com>
authored by