feat: collect 2 level files info when ls

* change cli dir to /usr/local/lib/cli
* refactor cli to multiple files
* add handleCommand and listeners pattern

packages/cli/watch.js

@@ -0,0 +1,6 @@
+const chokidar = require('chokidar')
+
+// One-liner for current directory
+chokidar.watch('.').on('all', (event, path) => {
+  console.log(event, path)
+})