Update README.md

Author: vzhou842

README.md

@@ -5,8 +5,8 @@ This is an example of a basic Javascript implementation of a bot for [generals.i
 ## Usage
 
 ```
-git clone https://github.com/vzhou842/generals.io-Node.js-Bot-example.git
-cd generals.io-Node.js-Bot-example
-npm install
-node main.js
+$ git clone https://github.com/vzhou842/generals.io-Node.js-Bot-example.git
+$ cd generals.io-Node.js-Bot-example
+$ npm install
+$ node main.js
 ```