Maintainer notes:

• Blocked on [modular] Decouple help format from help generation #2914 for decoupling help information gathering from formatting
• help2man can be a source of inspiration for how to integrate this into a users process

I'd love to have support to generate a manpage. This would use a mechanism and infrastructure similar to #376. Additional functions to override or augment portions of the generated manpage could come later, but I think with relatively few additions this could become an incredibly useful mechanism.

• The manpage title should default to the bin_name value.
• The section should default to 1.
• The NAME section should default to bin_name \- about, where about is the string set by .about.
• The SYNOPSIS section should contain the usage strings for the command and every subcommand.
• The DESCRIPTION section would need some new paragraph-style information provided (also usable as a more structured .before_help).
• The "OPTIONS" section should document the flags and args for the top-level command.
• If the command has subcommands, a "SUBCOMMANDS" section should document each subcommand in a sub-section.
• The AUTHORS section should contain the author information, if provided.
• The SEE ALSO section would need some new mechanism to populate it.

I'd be happy to help with manpage markup, once I see the details of the mechanism used in #376.