Update and cleanup repos command

[pvdz]

Update the repos command

• Fix the --json/--markdown cases where they make sense, remove them where they are unused
  • In the future we'll add them everywhere such that every command can do a json output (if nothing else a success/failure shape) but we're not there yet so I'm just removing it from commands that don't need it.
• Stop sending extra (irrelevant) data to the server
• Add a flag to the definition which is mandatory but since meow rejects unspecified flags it was impossible to use