Please provide a man page for obs-cli

[bdrung]

I am packaging obs-cli for Debian (see Debian bug #1000489). According to Debian, each binary in /usr/bin should have a manual page. See https://lintian.debian.org/tags/no-manual-page for more reasoning.

Please provide a man page for obs-cli. The man page should list which command and subcommand exists and what parameters they take. You can write the man page in Markdown and convert it to nroff. See https://github.com/bdrung/ionit/blob/master/ionit.1.md for an example.

[muesli]

Indeed, we should provide one. Since we're using Cobra, we can use it to automatically generate a man page from the command structure within obs-cli.

[muesli]

See progress in #33.