Document official Google calendar

.github/CODEOWNERS

@@ -24,3 +24,4 @@
 /doc/values.md @NixOS/steering
 /doc/constitution.md @NixOS/steering
 /doc/nixpkgs-committers.md @Mic92 @NickCao @jtojnar
+/doc/calendar.md @edolstra @grahamc @garbas @tomberek

README.md

@@ -26,3 +26,4 @@ For contributing see [here](./CONTRIBUTING.md).
 - [Governance](./doc/governance.md)
   - [Nix Governance Constitution](./doc/constitution.md)
   - [Nix Community Values](./doc/values.md)
+- [Calendar](./doc/calendar.md)

doc/calendar.md

@@ -0,0 +1,15 @@
+# Calendar
+
+There is [this official Google Calendar](https://calendar.google.com/calendar/u/0/[email protected]) ([ics](https://calendar.google.com/calendar/ical/b9o52fobqjak8oq8lfkhg3t0qg%40group.calendar.google.com/public/basic.ics)).
+
+These Google accounts have access to manage permissions (and make changes to events):
+<!-- Keep this list in sync with the codeowners of this file! -->
+- [email protected] (@edolstra)
+- [email protected] (@grahamc)
+- [email protected] (@garbas)
+- [email protected] (@tomberek)
+
+These people's Google following people can only make changes to events:
+- [email protected] (@fricklerhandwerk)
+- [email protected] (@infinisil)
+- [email protected] (@infinisil)