Drop jQuery dependency

docs/_templates/base.html

@@ -8,7 +8,7 @@
 {% block scripts %}
 {{ super() }}
 <script>
-jQuery(function ($) {
+document.addEventListener("DOMContentLoaded", function() {
   // Show banner linking to /stable/ if this is a /latest/ page
   if (!/\/latest\//.test(location.pathname)) {
     return;
@@ -16,18 +16,20 @@ jQuery(function ($) {
   var stableUrl = location.pathname.replace("/latest/", "/stable/");
   // Check it's not a 404
   fetch(stableUrl, { method: "HEAD" }).then((response) => {
-    if (response.status == 200) {
-      var warning = $(
-        `<div class="admonition warning">
-           <p class="first admonition-title">Note</p>
-           <p class="last">
-             This documentation covers the <strong>development version</strong> of Datasette.</p>
-             <p>See <a href="${stableUrl}">this page</a> for the current stable release.
-           </p>
-        </div>`
-      );
-      warning.find("a").attr("href", stableUrl);
-      $("article[role=main]").prepend(warning);
+    if (response.status === 200) {
+      var warning = document.createElement("div");
+      warning.className = "admonition warning";
+      warning.innerHTML = `
+        <p class="first admonition-title">Note</p>
+        <p class="last">
+          This documentation covers the <strong>development version</strong> of Datasette.
+        </p>
+        <p>
+          See <a href="${stableUrl}">this page</a> for the current stable release.
+        </p>
+      `;
+      var mainArticle = document.querySelector("article[role=main]");
+      mainArticle.insertBefore(warning, mainArticle.firstChild);
     }
   });
 });