Support basic formatting in the display of the description fields to
locations, events and shifts by rendering them as Markdown using the
micromark library.
Add a warning like display of event notices to the event card and the
event slot card and indicate in the timesheet that an event has a
notice. Also includes the input controls needed to edit the notice.
Pull out the list of events into its own page sorted by name and show
the event slots in chronological order on the schedule page, with past
slots hidden by default. This makes the content underneath the schedule
the most immediately useful to have in the moment, while the full list
is kept separately and in a predictable order.
