Add tutorial for creating Landsat 8 STAC

docs/tutorials.rst

@@ -27,10 +27,18 @@ How to create STAC Catalogs with PySTAC
 
 This was a tutorial that was part of a 30 minute presentation at the `community STAC sprint <https://github.com/radiantearth/community-sprints/tree/master/11052019-arlignton-va>`_ in Arlington, VA in November 2019. It runs through creating a STAC of image or label items from the `SpaceNet 5 <https://www.topcoder.com/challenges/30099956>`_ dataset.
 
+Creating a Landsat 8 STAC
+-------------------------
+
+- :tutorial:`GitHub version <creating-a-landsat-stac.ipynb>`
+- :ref:`Docs version </tutorials/creating-a-landsat-stac.ipynb>`
+
+This tutorial was presented at [Cloud Native Geospatial Outreach Day](https://sites.google.com/radiant.earth/cng-agenda/) on September 8th, 2020. It shows how to create a STAC collection from a subset of Landsat 8 scenes over a location.
+
 Adding New and Custom Extensions
 --------------------------------
 
-- :tutorial:`GitHub version <how-to-create-stac-catalogs.ipynb>`
+- :tutorial:`GitHub version <adding-new-and-custom-extensions.ipynb>`
 - :ref:`Docs version </tutorials/adding-new-and-custom-extensions.ipynb>`
 
 This tutorial goes over how to contribute new extensions to PySTAC as well as how to implement