format_help(
cmd) ->help
Generate markdown-formatted help text for a command
Returns a markdown string with the following sections:
# <command> — name heading## Usage — generated usage line## Options — pipe table with name, default, forms, and note columns## Arguments — pipe table with name, arity, default, and note columns## Subcommands — pipe table (when present)Inline code spans carry semantic classes for themed rendering:
.bool, .num, .str, .file, .dir.opt, .arg, .flag, .meta.req, .def, .multi, .neg