Fill in release date for 2.16.2

CHANGELOG.txt

@@ -69,7 +69,7 @@ Changelog
  * Fix: Ignore `GenericRelation` when copying pages (John-Scott Atlakson)
 
 
-2.16.2 (xx.xx.xxxx) - IN DEVELOPMENT
+2.16.2 (11.04.2022)
 ~~~~~~~~~~~~~~~~~~~
 
  * Fix: Update django-treebeard dependency to 4.5.1 or above (Serafeim Papastefanos)

docs/releases/2.16.2.md

@@ -1,4 +1,4 @@
-# Wagtail 2.16.2 release notes - IN DEVELOPMENT
+# Wagtail 2.16.2 release notes
 
 ```{contents}
 ---