docs: Fix links to man pages

[cgwalters]

Followup to #1587 Closes: #1616

[gemini-code-assist]

Code Review

This pull request fixes broken links to man pages across the documentation by updating filenames to include man page sections and correcting paths. The changes are mostly correct and improve the documentation's usability. I've added a couple of comments on docs/src/SUMMARY.md to point out some remaining inconsistencies in the content of two of the newly linked man pages for the sake of completeness. Addressing these would make the documentation fully consistent.

[jeckersb]

Not sure if I'm running this wrong with the new process, but I'm seeing this error trying to sanity check this:

$ just update-generated
[...]
Man pages updated.

Next steps for new templates:
   - Edit the templates to add detailed descriptions and examples
   - Run 'cargo xtask manpages' to generate final man pages

Updated docs/src/host-v1.schema.json
Updated docs/src/progress-v0.schema.json

I am assuming I am supposed to run cargo xtask manpages here, given the above output?

$ cargo xtask manpages
[...]
error: Man page filename must include section number (e.g., bootc.8.md, bootc-config.5.md): bootc-upgrade.md

[cgwalters]

OK yeah, there was some cruft and bugs here. Pushed another commit that fixes more things.

[cgwalters]

Now probably what might make sense is to try to extract this code into a standalone crate to replace https://docs.rs/clap_mangen/latest/clap_mangen/ for those who want what we're doing here (combining hand-maintained dedicated markdown with auto-generated options).

[cgwalters]

For the record what happened here is this one originally got a "control/skip-ci" label as it only affected docs, then it changed to change the code, but that didn't remove the label.

[cgwalters]

#1627