Enable building standalone doc for Builds 1.3

Author: eromanova97

_distro_map.yml

@@ -444,6 +444,9 @@ openshift-builds:
     build-docs-1.2:
       name: '1.2'
       dir: builds/1.2
+    build-docs-1.3:
+      name: '1.3'
+      dir: builds/1.3
 openshift-lightspeed:
   name: Red Hat OpenShift Lightspeed
   author: OpenShift documentation team <[email protected]>