Update README.md

Author: adavidw

README.md

@@ -4,21 +4,21 @@ This repository contains working code samples which demonstrate Node.js integrat
 The samples are organized just like our API, which you can also try out directly here: http://developer.authorize.net/api/reference
 
 
-##Using the Sample Code
+## Using the Sample Code
 
 The samples are all completely independent and self-contained so you can look at them to get a gist of how the method works, you can use the snippets to try in your own sample project, or you can run each sample from the command line.
 
-##Running the Samples  
-#Clone this repository.
-````
+## Running the Samples  
+### Clone this repository.
+```
     $ git clone https://github.com/AuthorizeNet/sample-code-nodejs.git
-````  
-# Install the SDK
-````
+```  
+### Install the SDK
+```
     $ npm install authorizenet
-````
+```
 
-# Run Sample Code
-````
+### Run Sample Code
+```
     $ node PaymentTransactions\authorize-credit-card.js
-````
+```