Update info about old images

Author: mathbunnyru

README.md

@@ -25,6 +25,11 @@ and want to launch a single Jupyter Application in a container.
 
 The [User Guide on ReadTheDocs](https://jupyter-docker-stacks.readthedocs.io/en/latest/) describes additional uses and features in detail.
 
+```{note}
+Since `2023-10-20` our images are only pushed to `Quay.io` registry.
+Older images are available on Docker Hub, but they will no longer be updated.
+```
+
 ### Example 1
 
 This command pulls the `jupyter/scipy-notebook` image tagged `2023-10-31` from Quay.io if it is not already present on the local host.
@@ -100,17 +105,17 @@ more information is available in the [documentation](https://jupyter-docker-stac
 This project only builds one set of images at a time.
 If you want to use older `Ubuntu` and/or `python` version, you can use following images:
 
-| Build Date   | Ubuntu | Python | Registry  | Tag            |
-| ------------ | ------ | ------ | --------- | -------------- |
-| 2022-10-09   | 20.04  | 3.7    | docker.io | `1aac87eb7fa5` |
-| 2022-10-09   | 20.04  | 3.8    | docker.io | `a374cab4fcb6` |
-| 2022-10-09   | 20.04  | 3.9    | docker.io | `5ae537728c69` |
-| 2022-10-09   | 20.04  | 3.10   | docker.io | `f3079808ca8c` |
-| 2022-10-09   | 22.04  | 3.7    | docker.io | `b86753318aa1` |
-| 2022-10-09   | 22.04  | 3.8    | docker.io | `7285848c0a11` |
-| 2022-10-09   | 22.04  | 3.9    | docker.io | `ed2908bbb62e` |
-| 2023-05-30   | 22.04  | 3.10   | docker.io | `4d70cf8da953` |
-| weekly build | 22.04  | 3.11   | quay.io   | `latest`       |
+| Build Date   | Ubuntu | Python | Tag            |
+| ------------ | ------ | ------ | -------------- |
+| 2022-10-09   | 20.04  | 3.7    | `1aac87eb7fa5` |
+| 2022-10-09   | 20.04  | 3.8    | `a374cab4fcb6` |
+| 2022-10-09   | 20.04  | 3.9    | `5ae537728c69` |
+| 2022-10-09   | 20.04  | 3.10   | `f3079808ca8c` |
+| 2022-10-09   | 22.04  | 3.7    | `b86753318aa1` |
+| 2022-10-09   | 22.04  | 3.8    | `7285848c0a11` |
+| 2022-10-09   | 22.04  | 3.9    | `ed2908bbb62e` |
+| 2023-05-30   | 22.04  | 3.10   | `4d70cf8da953` |
+| weekly build | 22.04  | 3.11   | `latest`       |
 
 ## Contributing