Add warning to docs about providing release notes when creating a tag

doc/user/project/releases/index.md

@@ -130,7 +130,11 @@ release creation, the release job fails.
 #### CI/CD example of the `release` keyword
 
 To create a release when you push a Git tag, or when you add a Git tag
-in the UI by going to **Repository > Tags**:
+in the UI by going to **Repository > Tags**: 
+
+NOTE:
+Do not provide **Release notes** when you create the Git tag in the UI.
+Providing release notes creates a release, resulting in the pipeline failing.
 
 ```yaml
 release_job: