Increase frequency of English HTML documentation builds (#604)

Author: AA-Turner

salt/docs/init.sls

@@ -110,15 +110,15 @@ docsbuild-only-html:
 
 docsbuild-only-html-en:
   cron.present:
-    # run twice hourly at HH:16 and HH:46
+    # run every five minutes, starting at HH:01
     - identifier: docsbuild-only-html-en
     - name: >
         /srv/docsbuild/venv/bin/python
         /srv/docsbuild/scripts/build_docs.py
         --select-output=only-html-en
         --languages=en
     - user: docsbuild
-    - minute: 16,46
+    - minute: '1-59/5'
     - require:
       - cmd: virtualenv-dependencies