Mailingliste: Add certain Issues to C-Base-Reminder Mail

[FFHener]

Since we have @Akira25's reminder bot which posts automatically an Invitation to our C-Base-Meetings it might be nice to add an overview of topics that needs to be discussed e.g. Issues that are marked with the label "Need for discussion".

The Github API already provides the tooling to just get a list of all issues with a certain label.

[Akira25]

Feel free to add it. :) I've published the code here:

https://github.com/freifunk-berlin/CommBot