Rearrange the settings in the example dunstrc and the manpage into broad
categories according to the part of the program they affect: Display,
text, icons, history and misc.
A middle click on an notification with a single or default action will
invoke it. If there are multiple actions and no default, the context
menu is opened. If there are no actions, proceed similarly with URLs.
Practically rewrite the entire manpage to focus more on the
configuration rather than the command line flags. Additionally, expand
more on how many of the settings work and on some of the less documented
functions (e.g. rules).
Move README to docs/dunst.pod to be used as man page. Write a README with building instructions and dependencies. Remove INSTALL as it's no longer necessary.
