feat(v2): add search page (#2756)

packages/docusaurus-plugin-content-docs/src/theme/hooks/useVersioning.ts

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+let versions: string[] = [];
+
+try {
+  versions = require('@site/versions.json');
+} catch (e) {}
+
+function useVersioning() {
+  return {
+    versioningEnabled: versions.length > 0,
+    versions,
+    latestVersion: versions[0],
+  };
+}
+
+export default useVersioning;