Fix up Tutorials landing page and Tutorials left nav. (#8557)

* Fix up Tutorials landing page and Tutorials left nav.

* Add redirects. Fix bullet.

static/example-templates/example-tutorial-template.md

@@ -0,0 +1,67 @@
+---
+title: Example Tutorial Template
+reviewers:
+- chenopis
+content_template: templates/tutorial
+---
+
+{{% capture overview %}}
+
+**NOTE:** Be sure to also [create an entry in the table of contents](/docs/home/contribute/write-new-topic/#creating-an-entry-in-the-table-of-contents) for your new document.
+
+This page shows how to ...
+
+{{% /capture %}}
+
+{{% capture prerequisites %}}
+
+* {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
+* Do this.
+* Do this too.
+
+{{% /capture %}}
+
+{{% capture objectives %}}
+
+* Learn this.
+* Build this.
+* Run this.
+
+{{% /capture %}}
+
+{{% capture lessoncontent %}}
+
+## Building ...
+
+1. Do this.
+1. Do this next. Possibly read this [related explanation](...).
+
+## Running ...
+
+1. Do this.
+1. Do this next.
+
+## Understanding the code
+Here's something interesting about the code you ran in the preceding steps.
+
+{{% /capture %}}
+
+{{% capture cleanup %}}
+
+**[Optional Section]**
+
+* Delete this.
+* Stop this.
+
+{{% /capture %}}
+
+{{% capture whatsnext %}}
+
+**[Optional Section]**
+
+* Learn more about [Writing a New Topic](/docs/home/contribute/write-new-topic/).
+* See [Using Page Templates - Tutorial template](/docs/home/contribute/page-templates/#tutorial_template) for how to use this template.
+
+{{% /capture %}}
+
+