Document Custom TMT test plans (#1039)

Document Custom TMT test plans

Related to packit/packit-service#2713.

Reviewed-by: František Lachman <flachman@redhat.com>
Reviewed-by: Nikola Forró
Reviewed-by: Laura Barcziová

Author: softwarefactory-project-zuul[bot]

fedora-ci/jobs.md

@@ -12,8 +12,11 @@ Scratch builds in [Koji](https://koji.fedoraproject.org/koji/) built from SCM.
 ### Installability
 
 [Installability test](https://github.com/fedora-ci/installability-pipeline)
-in [Testing Farm](https://testing-farm.io) run with a successfull scratch build.
+in [Testing Farm](https://testing-farm.io) run with a successful scratch build.
 
 ### Custom test plans
 
-TBD (The work is planned.)
+Custom [TMT](https://tmt.readthedocs.io/) test plans in [Testing Farm](https://testing-farm.io)
+run with a successful scratch build. This requires TMT metadata (`.fmf/version` presence used as an indicator)
+in the dist-git repository and at least one [test plan](https://tmt.readthedocs.io/en/stable/spec/plans.html)
+in `plans`.

fedora-ci/retriggering.md

@@ -29,7 +29,9 @@ To retrigger a specific test, you can add the test identifier to the command:
 /packit-ci test installability
 ```
 
-`installability` is the only supported identifier so far and it represents
-the [Installability](fedora-ci/jobs#installability) test.
+Currently supported identifiers are:
+
+- `installability` - represents the [Installability](/fedora-ci/jobs#installability) test
+- `custom` - represents [Custom TMT test plans](/fedora-ci/jobs#custom-test-plans)
 
 Only packagers can retrigger tests.