Better sorting for list of IRC bot macros

The list of IRC bot macros can be found at https://ircbot.ocf.berkeley.edu/macros.

(These are usable from within IRC/Slack by typing #m macronamehere)

Alphabetical sorting isn’t particularly useful, so we should make this page more sophisticated by allowing for other sorting methods. The easiest method would be based on when each macro is added (with more recently added macros shown first), but I also think a popularity metric could be useful too. Such a metric would probably require adding a new column to the MySQL store.