Update calendar to public Google Calendar (#36)

* Update calendar to public Google Calendar

* Add maintainer notes

Author: VeckoTheGecko

CONTRIBUTING.md

@@ -1 +1,17 @@
+# Contributing
+
 TODO
+
+## Maintainer notes
+
+### Onboardings
+
+Steering Council:
+
+- Give user admin permissions (add as admin for GitHub Org, add to admin on the Zulip)
+- Invite user to shared public Google Calendar for CLAM Community
+- Share login for CLAM Community Gmail account (`the.clam.community at gmail.com`) which has the shared documents inside
+
+Moderator:
+
+- Give moderator access in Zulip

docs/calendar.md

@@ -1,5 +1,5 @@
 # Calendar
 
-_Full calendar coming soon!_
+See below the CLAM Community calendar. Want to list an event? Message in the Zulip and ping `@Steering Council`. Note the listed timezone.
 
-The first meeting of the CLAM Community will be on Tuesday 28 October 2025 from 16:00 - 17:00 Central European Time (CET). Check out our Zulip (the `#announcements` channel) for more details!
+<iframe src="https://calendar.google.com/calendar/embed?src=be258142945481a85ddc678a80d0d24a6d202a2eabbcafff48ab2a784b9d01cf%40group.calendar.google.com&ctz=Europe%2FAmsterdam" style="border: 0" width="1024" height="900" frameborder="0" scrolling="no"></iframe>