Research: How to store calendar/event entries?

What is the most flexible way of storing calendar/event entries to ensure they are easy to query/search for and display in our intuitive UI https://github.com/dwyl/team-calendar/issues/1

> **Note**: our "_solution_" should _persist_ **`new`** calendar `events` back into the person's `Google` Calendar.
However to make them searchable and viewable by everyone we need to store them in our own database which
is kept in Sync with GCal.

Start with the requirements in this issue and the linked team-calendar issue #1, focusing on querying, searching, displaying, and synchronizing entries with Google Calendar. Done means documenting a storage approach that keeps new events persistent in Google Calendar while maintaining a searchable database copy.

Written by the indexing model from the issue text.