Merge pull request #81 from pattern-lab/dev

add new flag from core

Author: bmuenzenmeyer

patternlab-config.json

@@ -64,5 +64,6 @@
     "rendered": ".rendered",
     "rawTemplate": "",
     "markupOnly": ".markup-only"
-  }
+  },
+  "cleanOutputHtml": true
 }