Matrix Widget to Monitor m.room.member events

This widget shows a list of all m.room.member events of all rooms. It will only show events that are received while the widget is open.

How to use:

1. /addwidget https://dhenneke-element-bug-invite.netlify.app/
2. Open the widget.
3. Receive an invitation in the background.

See also element-hq/element-web#20622