Update ci_documentation_update.yml

Fixes issue with missing top level permissions (sets to read so any future job will have that as max).  Current jobs already have explicit permissions.

.github/workflows/ci_documentation_update.yml

@@ -1,5 +1,7 @@
 
 name: Publish Github Pages Template
+permissions: read-all
+
 on:
   workflow_call:
   workflow_dispatch: