Convert docdock theme from submodule to native files and fix Hugo compatibility

themes/docdock/assets/js/layouts/partials/menu.js

@@ -0,0 +1,18 @@
+const matches = document.querySelectorAll(`li[data-nav-id$="${window.location.pathname}"]`);
+if (matches.length > 0) {
+    const menu = matches[0];
+    menu.classList.add("active");
+
+    let maxDepth = 10; // Avoid infinite loop !
+    let nextAncestor = menu.closest("li[data-nav-id]");
+    while (maxDepth-- >= 0 && nextAncestor !== null) {
+        nextAncestor.classList.add("parent");
+        let icon = nextAncestor.querySelector('i.category-icon');
+        if (icon !== null) {
+            icon.classList.remove('fa-angle-right');
+            icon.classList.add('fa-angle-down');
+        }
+
+        nextAncestor = nextAncestor.parentNode.closest("li[data-nav-id]");
+    }
+}