Possibly provide event organizers with aggregate event statistics

[MoralCode]

the bot is in a somewhat unique position and has access to data like:

• event start time and end time
• total number of event registrations
• total number of people invited to matrix
• total members in matrix (accepted invites)

this is all aggregate/nonpersonal data that could be tracked by an organization over time to help them run events better by seeing how much falloff there is in the "pipeline" of attendance from registrations -> invites -> attendance -> participation