Rename docmuments subcommand: create <=> add?

[eskombro]

With meili-cli help you get this information:

...
SUBCOMMANDS:
    documents    create, delete, update and list documents
    help         Prints this message or the help of the given subcommand(s)
    index        create, delete, update and list indexes
    search       perform search
    settings     update indexes settings

but documents create is not recognized by the CLI. It likes documents add, instead!

🎉 Nice CLI