Include command line options in the man page

[lucc]

The man page does not list all command line options because I was to lazy to type them all again. There are solutions that can import argparse objects into sphinx documents.

Extracted from #285 (comment):

I found my branch and it uses https://github.com/alex-rudakov/sphinx-argparse to include the argparse stuff into the sphinx document, so that one does not have to type all the options and docs again. (There a quite a lot options in khard :)

I just played around with the branch again and noticed the following (i pushed the branch to github, so you can have a look: feature/auto-man):

• the sphinx plugin generates a full listing which is quite long
• It seems one can add extra text between the parts that are auto generated which I think is good, but I have not tested this yet
• there is a bug upstream Missing hyphens alex-rudakov/sphinx-argparse#115 which was not fixed for a long time but which immediately would affect us
• it is unclear if and where the project is active: Are you looking for a new maintainer? alex-rudakov/sphinx-argparse#135 (although github says it's used by 1.7k other repositories cry )

I am not really sure if I want to use that,, I will wait for an upstream decision first. If you know of any other alternatives, I am happy to hear them.

[pacien]

By the way, the manual page doesn't seem to be installed with the NixOS package.

[lucc]

Fixed with 799083f.