Chore: Hugo upgrade (#17494)

* Fix: Upgrade hugo wip

* Chore: Rename index to _index for latest hugo

* Chore: Use relative refs, no starting slash

* Feat: Add possibility to mount layouts from grafana.org project

packages/grafana-runtime/package.json

@@ -16,8 +16,7 @@
   },
   "author": "Grafana Labs",
   "license": "Apache-2.0",
-  "dependencies": {
-  },
+  "dependencies": {},
   "devDependencies": {
     "awesome-typescript-loader": "^5.2.1",
     "lodash": "^4.17.10",