Simplify mkdocs jquery inclusion by using overrides

instead of partials

docs/overrides/main.html

@@ -0,0 +1,10 @@
+{% extends "base.html" %}
+
+{% block footer %}
+    {{ super() }}
+
+    <!-- Place this tag in your head or just before your close body tag. -->
+    <script async defer src="https://buttons.github.io/buttons.js"></script>
+    <script src="https://code.jquery.com/jquery-3.4.1.min.js"
+      integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo=" crossorigin="anonymous"></script>
+{% endblock %}