make button focus a little more situational

scripts/nav.js

@@ -107,18 +107,11 @@ dropdownButton.addEventListener("keydown", (event) => {
 });
 
 firstDropdownItem.addEventListener("keydown", (event) => {
-  if (event.key === "Tab" && event.shiftKey) {
-    event.preventDefault();
-    closeDropdown();
-    dropdownButton.focus();
-  }
+  if (event.key === "Tab" && event.shiftKey) closeDropdown();
 });
 
 lastDropdownItem.addEventListener("keydown", (event) => {
-  if (event.key === "Tab" && !event.shiftKey) {
-    event.preventDefault();
-    closeDropdown();
-  }
+  if (event.key === "Tab" && !event.shiftKey) closeDropdown();
 });
 
 document.addEventListener("keydown", (event) => {