Add promise sample 🙌

Author: sicktastic

promises/calculation.js

@@ -0,0 +1,24 @@
+// We will transform this to promise
+// setTimeout(function() {
+//   console.log(1 + 1);
+// }, 1000)
+
+var calculationPromise = new Promise(function(resolve, reject) {
+  setTimeout(function() {
+    console.log(1 + 1);
+  }, 1000)
+});
+
+function addTwo(value) {
+  return value + 2;
+}
+
+function printFinalValue(nextValue) {
+  console.log("The final value is ", nextValue);
+}
+
+calculationPromise
+  .then(addTwo)
+  .then(printFinalValue);
+
+// Easy to read