feat(cli): Automatically generate man page

Instead of using a static one, generate it via clap_mangen. To generate
the manpage run `rosenpass --generate-manpage <folder>`.

Right now clap does not support flattening of generated manpages,
meaning that each subcommand is explained in its own file. To add extra
sections to the main file `rosenpass.1`, it's rewritten after the
initial creation.

Once clap support flattened Man pages, the `generate_to` call can be
removed and all subcommand are added to the `rosenpass.1` file.

This implementation allows downstream manpage generation to stay
unchanged even after switching from multiple manpages to a flattened
one.

Signed-off-by: Paul Spooren <mail@aparcar.org>

.github/workflows/qc.yaml

@@ -62,8 +62,6 @@ jobs:
       - name: Install mandoc
         run: sudo apt-get install -y mandoc
       - uses: actions/checkout@v3
-      - name: Check rosenpass.1
-        run: doc/check.sh doc/rosenpass.1
       - name: Check rp.1
         run: doc/check.sh doc/rp.1