Update README for ubuntu-26.04 image

Author: Greelan

README.md

@@ -11,9 +11,10 @@ Currently maintained image tags:
 | [debian](https://github.com/CubeCoders/dockerfiles/tree/master/base/debian/Dockerfile), latest       | The primary AMP base image, used for most AMP instances that are run in Docker/Podman. Currently based on Debian 13. Usually updated to the current stable Debian release after the first point release |
 | [debian-12](https://github.com/CubeCoders/dockerfiles/tree/master/base/debian-12/Dockerfile)         | An alternate AMP base image, based on Debian 12. This is available for applications that need oldstable Debian                                                                                          |
 | [ubuntu](https://github.com/CubeCoders/dockerfiles/tree/master/base/ubuntu/Dockerfile)               | An alternate AMP base image, currently based on Ubuntu 24.04. Usually updated to the current Ubuntu LTS release after the first point release                                                           |
+| [ubuntu-26.04](https://github.com/CubeCoders/dockerfiles/tree/master/base/ubuntu-26.04/Dockerfile)   | An alternate AMP base image, based on Ubuntu 26.04. Will become the `ubuntu` image after the first point release                                                                                        |
 | [java-lts](https://github.com/CubeCoders/dockerfiles/tree/master/java/lts/Dockerfile), java          | An image based on the `debian` image, incorporating Adoptium Eclipse Temurin Java 8, 11, 17, 21 (default) and 25 LTS builds from https://adoptium.net                                                   |
 | [java-25](https://github.com/CubeCoders/dockerfiles/tree/master/java/25/Dockerfile)                  | An image based on the `debian` image, incorporating Adoptium Eclipse Temurin Java 25 LTS build from https://adoptium.net                                                                                |
-| [python-3](https://github.com/CubeCoders/dockerfiles/tree/master/python/3/Dockerfile), python3       | An image based on the `debian` image, incorporating official builds for Python 3.10, 3.11, 3.12, 3.13 (default) and 3.14                                                                                 |
+| [python-3](https://github.com/CubeCoders/dockerfiles/tree/master/python/3/Dockerfile), python3       | An image based on the `debian` image, incorporating official builds for Python 3.10, 3.11, 3.12, 3.13 (default) and 3.14                                                                                |
 | [python-3.10](https://github.com/CubeCoders/dockerfiles/tree/master/python/3.10/Dockerfile)          | An image based on the `debian` image, incorporating the official build for Python 3.10                                                                                                                  |
 | [python-3.11](https://github.com/CubeCoders/dockerfiles/tree/master/python/3.11/Dockerfile)          | An image based on the `debian` image, incorporating the official build for Python 3.11                                                                                                                  |
 | [python-3.12](https://github.com/CubeCoders/dockerfiles/tree/master/python/3.12/Dockerfile)          | An image based on the `debian` image, incorporating the official build for Python 3.12                                                                                                                  |