Order exercise folders

Ordered the exercise folders by placing their numbers in their folder name

01 helloWorld/helloWorld.spec.js

@@ -0,0 +1,7 @@
+const helloWorld = require('./helloWorld');
+
+describe('Hello World', function() {
+  test('says "Hello, World!"', function() {
+    expect(helloWorld()).toEqual('Hello, World!');
+  });
+});