fix(app.js): Fix app.js typo (#5)

trustedtomato · briancavalier · commit 21b61e4923f2 · 2017-06-20T08:46:20.000-04:00
diff --git a/drag-n-drop/app.js b/drag-n-drop/app.js
@@ -4648,7 +4648,7 @@ exports.periodic = periodic;
 /**
  * Create a stream that emits the current time periodically
  * @param {Number} period periodicity of events in millis
- * @param {*) value value to emit each period
+ * @param {*} value value to emit each period
  * @returns {Stream} new stream that emits the current time every period
  */
 function periodic(period, value) {
