Feature (or Component): Personal schedule

to be able to add individual events or full sessions of interest.

Re mini-conf: https://github.com/Mini-Conf/Mini-Conf/issues/83#issuecomment-656352983 for ACL2020 - a nice "workaround" to just allow to add to the "personal" calendar of interest (google etc). That would allow "centralization" and "overlay" with a truly personal one. Then it could be extended with ability to "link back" `.ical` and then we could display "personal calendar" and also fulfill the idea of "automatically jump between the events according to personal calendar". Might be quite neat and without requiring "a database" backend to host those personal calendars etc.