Set up project skeleton for flipper-pkg

Summary: TypeScript cli tool basics.

Reviewed By: jknoxville, nikoant

Differential Revision: D19856513

fbshipit-source-id: da148d1435c09221f74dc94285b655bed53d0494

pkg/src/index.ts

@@ -0,0 +1,12 @@
+/**
+ * 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.
+ *
+ * @format
+ */
+
+(async () => {
+  console.log('Hello, flipper-pkg.');
+})();