Fixing KaTeX in docs (#332)

Author: akoutmos

mix.exs

@@ -126,11 +126,14 @@ defmodule Scholar.MixProject do
 
   defp before_closing_body_tag(:html) do
     """
-    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.13.0/dist/katex.min.css" integrity="sha384-t5CR+zwDAROtph0PXGte6ia8heboACF9R5l/DiY+WZ3P2lxNgvJkQk5n7GPvLMYw" crossorigin="anonymous">
-    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.13.0/dist/katex.min.js" integrity="sha384-FaFLTlohFghEIZkw6VGwmf9ISTubWAVYW8tG8+w2LAIftJEULZABrF9PPFv+tVkH" crossorigin="anonymous"></script>
-    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.13.0/dist/contrib/auto-render.min.js" integrity="sha384-bHBqxz8fokvgoJ/sc17HODNxa42TlaEhB+w8ZJXTc2nZf1VgEaFZeZvT4Mznfz0v" crossorigin="anonymous"></script>
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.4/dist/katex.min.css" integrity="sha384-vKruj+a13U8yHIkAyGgK1J3ArTLzrFGBbBc0tDp4ad/EyewESeXE/Iv67Aj8gKZ0" crossorigin="anonymous">
+    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.16.4/dist/katex.min.js" integrity="sha384-PwRUT/YqbnEjkZO0zZxNqcxACrXe+j766U2amXcgMg5457rve2Y7I6ZJSm2A0mS4" crossorigin="anonymous"></script>
+    <link href="https://cdn.jsdelivr.net/npm/katex-copytex@1.0.2/dist/katex-copytex.min.css" rel="stylesheet" type="text/css">
+    <script defer src="https://cdn.jsdelivr.net/npm/katex-copytex@1.0.2/dist/katex-copytex.min.js" crossorigin="anonymous"></script>
+    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.16.4/dist/contrib/auto-render.min.js" integrity="sha384-+VBxd3r6XgURycqtZ117nYw44OOcIax56Z4dCRWbxyPt0Koah1uHoK0o4+/RRE05" crossorigin="anonymous"></script>
+
     <script>
-      document.addEventListener("DOMContentLoaded", function() {
+      window.addEventListener("exdoc:loaded", () => {
         renderMathInElement(document.body, {
           delimiters: [
             { left: "$$", right: "$$", display: true },
@@ -139,6 +142,7 @@ defmodule Scholar.MixProject do
         });
       });
     </script>
+
     <script src="https://cdn.jsdelivr.net/npm/vega@5.20.2"></script>
     <script src="https://cdn.jsdelivr.net/npm/vega-lite@5.1.1"></script>
     <script src="https://cdn.jsdelivr.net/npm/vega-embed@6.18.2"></script>