add redirect test workflow / github action

.test/README.md

@@ -8,6 +8,14 @@ Test specifications are currently extracted from .htaccess file comments, e. g.
 ##TESTv1 '/mypath --header "Accept: text/html"' "https://my-target-domain.com/test.html"
 ```
 
+## Run the test as Github Action
+1. Navigate to `https://github.com/<your fork>/w3id.org/actions/workflows/redirect_tests.yml` (example see [here](https://github.com/OpenSemanticWorld/w3id.org/actions/workflows/redirect_tests.yml))
+1. Select 'Run workflow'
+1. Keep the master branch or select your custom branch
+1. Change the subpath to your subpath, e.g. `/mypath`
+1. Click 'Run workflow'
+1. After completion, click on the run entry to view details (example see [here](https://github.com/OpenSemanticWorld/w3id.org/actions/runs/7224639650/job/19686349546))
+
 ## Run the test locally
 Note: replace `/*` with your own trusted subpath, e.g. `/mypath`, otherwise all subpaths are tested which may create security issues
 ```bash