Fix link to scale subresource

add missing leading /

Author: dbenque

content/en/docs/tasks/run-application/configure-pdb.md

@@ -49,7 +49,7 @@ specified by one of the built-in Kubernetes controllers:
 In this case, make a note of the controller's `.spec.selector`; the same
 selector goes into the PDBs `.spec.selector`.
 
-From version 1.15 PDBs support custom controllers where the [scale subresource](docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/#scale-subresource) is enabled.
+From version 1.15 PDBs support custom controllers where the [scale subresource](/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/#scale-subresource) is enabled.
 
 You can also use PDBs with pods which are not controlled by one of the above
 controllers, or arbitrary groups of pods, but there are some restrictions,