Split tmt plans into separate zuul jobs

This should improve the experience by having separate clickable
links for each test matrix item and see the pass/fail more early.
Also make Testing Farm scale better as it uses separate TF requests
for testing.

Signed-off-by: Miroslav Vadkerti <mvadkert@redhat.com>

README.md

@@ -1,3 +1,4 @@
+
 # fedora-kiwi-descriptions
 
 This project is used to manage the Fedora KIWI image descriptions used in composing Fedora release images.
@@ -30,6 +31,13 @@ Set up your development environment and run the image build (substitute `<image_
 This project is tested using the [Software Factory Zuul CI instance](https://fedora.softwarefactory-project.io/zuul/project/pagure.io/fedora-kiwi-descriptions)
 using the [Test Management Tool](https://tmt.readthedocs.io/).
 
+The Zuul configuration is generated from the Jinja2 template `.zuul.yaml.j2`.
+When adding or removing a tmt plan, please run the following command to regenerate the Zuul configuration:
+
+```bash
+[]$ make generate-zuul-config
+```
+
 ## Licensing
 
 This is free software: you can redistribute it and/or modify