jobs/ttcn3-testsuites-kernel-git: make userfriendly

Change the description of the job, to make it easier to use for somebody
not familiar with the Osmocom stack / the testsuites. Move the BRANCH
parameter to the bottom, as it is not relevant for kernel developers who
want to test their kernel, and adjust the description.

Related: OS#3208
Change-Id: I0968ae716c8e3f32db6f589b28d6066d95ad85ea

jobs/ttcn3-testsuites-kernel-git.yml

@@ -19,8 +19,13 @@
           # Cache the linux source tree in the workspace of one node
           node: ttcn3-ggsn-test-kernel-git
           description: |
-            Test osmo-ggsn master with a kernel built from source (see build
-            parameters, by default: net-next.git from kernel.org).
+            Run the
+            <a href="https://osmocom.org/projects/cellular-infrastructure/wiki/Titan_TTCN3_Testsuites">
+              Osmocom Titan TTCN-3 testsuite</a> against
+            <a href="https://osmocom.org/projects/openggsn/wiki/OsmoGGSN">
+              OsmoGGSN</a> with the GTP kernel module. The kernel is built
+            from the git repository and branch provided as parameters when
+            starting this job.
 
 - job-template:
     name: '{job-name}'
@@ -30,12 +35,6 @@
     description: '{obj:description}'
     node: '{obj:node}'
     parameters:
-      - string:
-          name: BRANCH
-          description: |
-                Branch of <code>docker-playground.git</code>.
-                Only modify if you are hacking on the docker-playground scripts.
-          default: '*/master'
       - string:
           name: KERNEL_URL
           description: |
@@ -65,6 +64,13 @@
                 <code>latest</code> for the latest release version, or
                 <code>master</code> for HEAD of git.osmocom.org.
           default: 'latest'
+      - string:
+          name: BRANCH
+          description: |
+                Branch of <code>docker-playground.git</code>
+                (for development of the test infrastructure, don't change this
+                when testing kernel trees).
+          default: '*/master'
 
     builders:
       - shell: |-