test that we have the right man pages
Man pages don't show up in man/ automatically nor in see also sections. Test that:
- We have a man page for each command, plus
charliecloud(1), and no others. - Each man page appears in "See also" section in
charliecloud(1). - Blurbs in
doc-src/conf.pymatchcommand-usage.rstmatch the command help text.