Merge "zuul.d: add comments to describe zuul files layout"

zuul.d/base.yaml

@@ -1,4 +1,7 @@
 ---
+# zuul.d/base.yaml
+# This file contains parent layouts for all TripleO jobs.
+# Do not add children specific layout here.
 
 - job:
     name: tripleo-ci-dsvm
@@ -34,7 +37,6 @@
     name: tripleo-ci-dsvm-multinode
     description: |
       Base legacy job for multinode tripleo jobs.
-
       Ensures the firewall allows all traffic between test nodes.
     parent: tripleo-ci-dsvm
     roles:

zuul.d/build-image.yaml

@@ -1,4 +1,6 @@
 ---
+# zuul.d/build-image.yaml
+# Zuul layout for TripleO Build Image jobs.
 
 - project-template:
     name: tripleo-buildimage-jobs

zuul.d/layout.yaml

@@ -1,3 +1,8 @@
+---
+# zuul.d/layout.yaml
+# This file is the Zuul layout of openstack-infra/tripleo-ci project
+# It describes the jobs that will run when submitting a change in this
+# repository.
 
 - project:
     templates:

zuul.d/multinode-jobs.yaml

@@ -1,4 +1,7 @@
 ---
+# zuul.d/multinode-jobs.yaml
+# Zuul layout for TripleO multinode jobs.
+# It contains all the jobs using deployed-servers in nodepool.
 
 - project-template:
     name: tripleo-multinode-baremetal-minimal

zuul.d/undercloud-jobs.yaml

@@ -1,4 +1,7 @@
 ---
+# zuul.d/undercloud-jobs.yaml
+# Zuul layout for TripleO undercloud jobs.
+# It contains all the jobs related to undercloud testing.
 
 - project-template:
     name: tripleo-undercloud-jobs