feat: Initial search implementation using pagefind.

Sources/Docs/Templates/Header.swift

@@ -40,19 +40,7 @@ func generateHeader(
       meta(content: "1014", name: "og:image:width"),
       meta(content: "530", name: "og:image:height"),
       script(crossorigin: "anonymous", src: "https://kit.fontawesome.com/f209982030.js"),
-      Node.raw("""
-      <script>
-      MathJax = {
-        tex: {
-          inlineMath: [['$', '$']]
-        },
-        svg: {
-          fontCache: 'global'
-        }
-      };
-      </script>
-      """),
-      script(defer: true, src: "https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-svg.js")
+      script(src: "https://cdn.jsdelivr.net/npm/minisearch@7.1.2/dist/umd/index.min.js")
     ])
   }
 }