chore: remove element template scripts

Element templates feature was removed.

Author: philippfromme

package.json

@@ -19,8 +19,6 @@
     "start:cloud": "cross-env SINGLE_START=cloud npm run dev",
     "start:platform": "cross-env SINGLE_START=platform npm run dev",
     "start:bpmn": "cross-env SINGLE_START=bpmn npm run dev",
-    "start:templates": "cross-env SINGLE_START=templates npm run dev",
-    "start:cloud-templates": "cross-env SINGLE_START=cloud-templates npm run dev",
     "prepare": "run-s bundle"
   },
   "repository": {