debug: add mangen + nix: add completion/manpages to output

[colemickens]

Sorry, I didn't open an issue for this one. It started with a quick Nix fix and evolved. Let me know if you'd prefer it split, etc.

This:

1. adds clap_mangen to cargo
2. adds jj debug mangen subcommand
3. uses the debug subcommands in the nix expression to enrich the package outputs

clap_mangen suggest possibly using in a build task, but I prefer, and wanted to match, the internal debug command pattern already used for completions.

• Tests pass
• Appropriate changes to README are included in PR

To be honest, I don't know what is normally done to install manpages, hence the lack of README change. Mine just works via nixos/home-manager.

demo: https://asciinema.org/a/zyx09Y2SWz6FuEihbUupl5TP1

• first the nix config for a to-be-upstreamed home-manager module
• man jj showing the manpage
• jj <tab> showing completions
• jj status <tab> showing arg completions

(demo created by utilizing my existing configuration, then sudo nixos-rebuild ~/code/nixcfg#porty --override-input jj ~/code/jj, and then just ran zellij in asciinema)

[martinvonz]

Sorry, I didn't open an issue for this one.

No problem, I don't care about having an issue for each PR anyway. That was just something that came with Google's default PR template. I just merged a PR removing that from the template (#94).

It started with a quick Nix fix and evolved. Let me know if you'd prefer it split, etc.

This:

1. adds clap_mangen to cargo
2. adds jj debug mangen subcommand
3. uses the debug subcommands in the nix expression to enrich the package outputs

Looks good. I would have squashed 1 into 2 because the new dependency on its own isn't useful or tested.

clap_mangen suggest possibly using in a build task, but I prefer, and wanted to match, the internal debug command pattern already used for completions.

Thanks. One advantage of doing it in the debug command is that it's guaranteed to match the binary.

To be honest, I don't know what is normally done to install manpages, hence the lack of README change. Mine just works via nixos/home-manager.

https://askubuntu.com/questions/244809/how-do-i-manually-install-a-man-page-file says put it in /usr/local/share/man/man1/ (on Ubuntu anyway), but that can be done later.

demo: https://asciinema.org/a/zyx09Y2SWz6FuEihbUupl5TP1

• first the nix config for a to-be-upstreamed home-manager module
• man jj showing the manpage
• jj <tab> showing completions
• jj status <tab> showing arg completions

(demo created by utilizing my existing configuration, then sudo nixos-rebuild ~/code/nixcfg#porty --override-input jj ~/code/jj, and then just ran zellij in asciinema)

Nice. Thanks!