Update workshop notebook for HDNNP so that it looks nice in a jupyter book format.

_config.yml

@@ -28,3 +28,19 @@ repository:
 html:
   use_issues_button: false
   use_repository_button: true
+
+parse:
+  myst_enable_extensions:
+    # don't forget to list any other extensions you want enabled,
+    # including those that are enabled by default!
+    - html_image
+    - amsmath
+    - dollarmath
+    - linkify
+    - substitution
+    - colon_fence
+
+sphinx:
+  config:
+    mathjax_path: https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js
+