#3151 defer loading

Author: rjzupkoii

_includes/head/custom.html

@@ -14,7 +14,7 @@
 
 <!-- Support for MatJax -->
 <script async src="https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js?features=es6"></script>
-<script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
+<script async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js" id="MathJax-script"></script>
 
 <!-- Support for Mermaid -->
 <script type="module">
@@ -24,6 +24,6 @@
 </script>
 
 <!-- Support for Plotly -->
-<script async src='https://cdnjs.cloudflare.com/ajax/libs/plotly.js/3.0.1/plotly.min.js'></script>
+<script defer src='https://cdnjs.cloudflare.com/ajax/libs/plotly.js/3.0.1/plotly.min.js'></script>
 
 <!-- end custom head snippets -->