Generate man pages and shell completions

Produce man pages and useful completions for ironhide users.

We can [generate shell completions](https://kbknapp.dev/shell-completions/) using `clap` as part of our build process. See `ripgrep` for examples of including completions in the build artifacts.

We can also generate [man pages](https://docs.rs/clap_mangen/latest/clap_mangen/) for the tool in a similar way.