List people not attending

[tobiasKaminsky]

In protocols usually all people are mentioned.
On very strict meetings, there is then also added why people did not attend.

This might not be useful for every scenario, but having an option for it, feels like over-configuring it.
In the end any can copy and modify it to their needs.

[nickvergessen]

That's currently not possible as the bots can only react to chat messages and not-joining users don't create a chat message :P