Update README.md

Author: Greelan

README.md

@@ -6,9 +6,9 @@ These images are not designed to be run directly. Instead, they should be run vi
 
 Currently maintained image tags:
 
-- [debian](https://github.com/CubeCoders/dockerfiles/tree/master/base/debian): the primary AMP base image, used for most AMP instances, based on Debian 12
-- [debian-13](https://github.com/CubeCoders/dockerfiles/tree/master/base/debian-13): an alternate AMP base image, based on Debian 13
-- [ubuntu](https://github.com/CubeCoders/dockerfiles/tree/master/base/ubuntu): an alternate AMP base image, based on Ubuntu 24.04
+- [debian](https://github.com/CubeCoders/dockerfiles/tree/master/base/debian): the primary AMP base image, used for most AMP instances. Currently based on Debian 12. Usually updated to the current stable Debian release after the first point release
+- [debian-13](https://github.com/CubeCoders/dockerfiles/tree/master/base/debian-13): an alternate AMP base image, based on Debian 13. This is available for testing before the `debian` image is updated
+- [ubuntu](https://github.com/CubeCoders/dockerfiles/tree/master/base/ubuntu): an alternate AMP base image, currently based on Ubuntu 24.04. Usually updated to the current Ubuntu LTS release after the first point release
 - [java-lts](https://github.com/CubeCoders/dockerfiles/tree/master/base/java-lts): an image based on the `debian` image, incorporating Adoptium Eclipse Temurin Java 8, 11, 17 and 21 LTS builds from https://adoptium.net
 - [python-3](https://github.com/CubeCoders/dockerfiles/tree/master/base/python-3): an image based on the `debian` image, incorporating official builds for Python 3.10, 3.11 (default), 3.12 and 3.13
 - [python-3.10](https://github.com/CubeCoders/dockerfiles/tree/master/base/python-3.10): an image based on the `debian` image, incorporating the official build for Python 3.10