feat: Auto-focus select2 search fields when they open (ietf-tools#4599)

Author: larseggert

ietf/static/js/select2.js

@@ -39,6 +39,14 @@ window.setupSelect2Field = function (e) {
 
     template_modify = e.hasClass("tz-select") ? prettify_tz : undefined;
 
+    // focus the search field automatically
+    $(document)
+        .on("select2:open", () => {
+            document.querySelector(
+                    ".select2-container--open .select2-search__field")
+                .focus()
+        });
+
     e.select2({
         multiple: maxEntries !== 1,
         maximumSelectionSize: maxEntries,