docs/release-calendar: restore missing id

I'm not sure how this got dropped, but it somehow did during conversion.
Let's restore it.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4630>

diff --git a/docs/release-calendar.rst b/docs/release-calendar.rst
index 69e8e16..271b638 100644 (file)
--- a/docs/release-calendar.rst
+++ b/docs/release-calendar.rst
@@ -22,6 +22,8 @@ The way the release schedule works is explained
 Take a look `here <submittingpatches.rst#criteria>`__ if you'd like to
 nominate a patch in the next stable release.
 
+.. _calendar:
+
 Calendar
 --------