Add link to spacetime codes Youtube video in docs leftnav

Author: caleb-johnson

docs/index.rst

@@ -155,6 +155,12 @@ References
 
    Low overhead error detection using spacetime codes <guides/low_overhead_error_detection_using_spacetime_codes>
 
+.. toctree::
+   :hidden:
+   :caption: Learning resources
+
+   The research behind Paulice <https://www.youtube.com/watch?v=3Wpeo3Lv7Pw>
+
 .. toctree::
    :hidden:
    :caption: API reference