improve the description of the mailinglists (#299)

Signed-off-by: Felix Kronlage-Dammers <fkr@hazardous.org>
Co-authored-by: Kurt Garloff <kurt@garloff.de>

community/tools/mailinglists.md

@@ -1,5 +1,10 @@
 # Mailing Lists
 
-We have an announcements mailing list there `announce@lists.scs.community` and you
-can subscribe via the [mailman3 frontend](https://scs.sovereignit.de/mailman3/postorius/lists/)
-also without the SCS nextcloud account if you prefer.
+Together with [matrix](/community/tools/matrix) our mailing lists are central
+to our collaboration. Currently there is this set of mailing lists:
+
+- [SCS Community Announcements](https://scs.sovereignit.de/mailman3/postorius/lists/announce.lists.scs.community/) - This list is intended for announcements only. It is moderated. Everyone can subscribe to this list and if you want to stay in touch with SCS, you should subscribe to this list.
+
+- [SCS Tech Community List](https://scs.sovereignit.de/mailman3/postorius/lists/scs-tech.lists.scs.community/) - The overall list for anything related to technical discussions. Everyone can subscribe to this list. Furthermore all members of the SCS Community are automatically subscribed to this list.
+
+- SCS Members - Members of the SCS Community are automatically subscribed to this list. Announcements and discussions regarding the SCS Community are welcome here.