Show "TBD/TBA" locations to enable early, "save the date"-like announcements
Can we modify event_digest.html so that it falls back to whichever free-text the event organizer added after the
campus: field, in case the campii still needs to be decided? The code for
lecturer seems to do that, but @schlauch & me weren't sure how to adapt that templating code.
TBD campus could be added, however, sometimes at least the city or region can be added, like DLR would like to do in !159 (merged), !163 (merged) & !164 (merged). For example, the latter's result like this would be helpful to learners already: