Changelog: require Postgres 12 and PostGIS 3

CHANGELOG.md

@@ -34,13 +34,12 @@
   sudo add-apt-repository ppa:ubuntugis/ppa
   sudo apt-get update
 
-- Postgres 11 and PostGIS 2.5 is required, Postgres 12 and PostGIS 3 is
-  recommended. If Postgres needs to be updated, update directly to Postgres 12.
-  If both needs to be updated, update PostGIS first and run ``ALTER EXTENSION
-  postgis UPDATE;`` in every database. For docker-compose setups this database
-  update is performed automatically. If a replication setup is in use, the
-  database configuration changes for Postgres 12. CATMAID's replication
-  documentation explains what needs to be done.
+- Postgres 12 and PostGIS 3 are now required. If Postgres needs to be updated,
+  make sure to update PostGIS first and run ``ALTER EXTENSION postgis UPDATE;``
+  in every database. For docker-compose setups this database update is performed
+  automatically. If a replication setup is in use, the database configuration
+  changes for Postgres 12. CATMAID's replication documentation explains what
+  needs to be done.
 
 - The management command catmaid_populate_summary_tables is now known as
   catmaid_refresh_node_statistics.