Add disclaimer about unmerged prerequisites in README

README.md

@@ -8,6 +8,9 @@
 
 ---
 
+> [!WARNING]
+> Functionality of this addon depends on some unmerged features in the [mittwald CLI](https://github.com/mittwald/cli) (most importantly, https://github.com/mittwald/cli/pull/220). This warning will be removed once all required prerequisites have been merged. See https://github.com/mittwald/feature-requests/issues/118 to track the feature's overall progress.
+
 ## Synopsis
 
 This repository contains a [DDEV addon][addon] for the mittwald hosting platform. It adds the following features to your DDEV project:
@@ -43,4 +46,4 @@ Installing the mittwald DDEV addon allows you to use the following commands:
 [addon]: https://ddev.readthedocs.io/en/stable/users/extend/additional-services/
 [cli]: https://github.com/mittwald/cli
 [api-intro]: https://developer.mittwald.de/docs/v2/api/intro/
-[deployment]: https://developer.mittwald.de/docs/v2/category/deployment-guides/
+[deployment]: https://developer.mittwald.de/docs/v2/category/deployment-guides/