Add tags to events

For previous Bitcamps, we've had tags on the events - things such as "Beginner Friendly"

We could probably add some extra processing to the description field to simulate this, but I think it would be nice to have it officially supported.

No files, tests, or entry points are identified in the issue. Start by locating how events are stored and rendered in the dashboard, then determine the intended tag representation and presentation; the work is done when events officially support tags such as “Beginner Friendly” without relying on description text.

Written by the indexing model from the issue text.