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

docs/sources/tutorials/_index.md

@@ -0,0 +1,26 @@
++++
+title = "Tutorials"
+type = "docs"
+[menu.docs]
+identifier = "tutorials"
+weight = 6
++++
+
+# Tutorials
+
+This section of the docs contains a series for tutorials and stack setup guides.
+
+## Articles
+
+- [Running Grafana behind a reverse proxy]({{< relref "behind_proxy.md" >}})
+- [API Tutorial: How To Create API Tokens And Dashboards For A Specific Organization]({{< relref "api_org_token_howto.md" >}})
+- [How to Use IIS with URL Rewrite as a Reverse Proxy for Grafana on Windows]({{< relref "iis.md" >}})
+- [How to integrate Hubot with Grafana]({{< relref "hubot_howto.md" >}})
+- [How to setup Grafana for high availability]({{< relref "ha_setup.md" >}})
+
+## External links
+
+- [Installing Graphite and Grafana on RHEL 6, 7, or Ubuntu in under 30 minutes](http://blog.pkiwi.com/installing-graphite-and-grafana-on-rhel-6-7-or-ubuntu-in-under-30-minutes/)
+- [Monitoring Urbancode deployments with Docker, Graphite, Grafana, collectd and chef!](http://cloud.boriskuschel.com/2015/08/monitoring-urbancode-deploments-with.html)
+- [Scripting Grafana dashboards](http://anatolijd.blogspot.se/2014/07/scripting-grafana-dashboards.html)
+