Can be executed with rofi-bang. It will take a comma-separated list of
commands (for now statically sourced from rofi config dir), show labels
and 'bangs' for them (in the manner of !c or !yt) which, if typed will
instantly execute their command. In this manner, it becomes possible to
create a quickly accessible menu using rofi.
E.g. we could have !b to search bookmarks. As soon as !b is typed the
'bang' instance of rofi exits and executes the associated command. If
the command starts up another, visually identical, rofi instance with a
preselection of different user bookmarks, it appears as if we just
jumped into a bookmark list in the same rofi instance.
Of course, the commands can be anything. They don't have to invoke more
rofi instances.
