Add a list of system and general keyboard shortcuts as well as a list
of tips and tricks to man7 (Miscellanea). Add links to these in the
Help-index to aid discoverability for new users.
The URLs of the form `help://man/<section>/<page>` link to another help
page inside the help application. All previous relative page links are
replaced by this new form. This doesn't change any behavior but it looks
much nicer :^)
Note that man doesn't handle these new links, but the previous relative
links didn't work either.
