Add configuration for jenkins location

Location url is used to let Jenkins
know how to refer to itself

Change-Id: I44ac0d271d38e4c04721df605142f44345736cf2
Related-bug: PROD-26834
             PROD-30275
(cherry picked from commit I44ac0d271d38e4c04721df605142f44345736cf2)
diff --git a/README.rst b/README.rst
index d21f47f..42bcbeb 100644
--- a/README.rst
+++ b/README.rst
@@ -188,6 +188,8 @@
           host: jenkins.example.com
           port: 80
           protocol: http
+        location:
+          url: http://jenkins.example.com:80
         job:
           jobname:
             type: workflow