austin: add draft EN transcript (#186)

* austin: add draft EN transcript

* add transcript to menu

* modify toctree hierarchy and clean up handful of paragraphs

* clean couple of paragraphs

* clean up RS intro

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Co-authored-by: Oriol (ZBook) <[email protected]>

Author: reshamas

about/probabilistic_programming_with_pymc/index.md

@@ -34,4 +34,5 @@ Austin Rochford is the Chief Data Scientist at Kibo Commerce. He is a recovering
 :hidden:
 
 Webinar notebook <notebook>
+Video transcript <transcript>
 :::