Updated Using Azure SDK for Ruby (markdown)

Using-Azure-SDK-for-Ruby.md

@@ -1,5 +1,5 @@
 This page will help users in setting up the environment and using the Azure SDK for Ruby.
 
 1. [Prerequisites](https://github.com/Azure/azure-sdk-for-ruby/wiki/Prerequisites)
-2. Installing Azure Ruby SDK
+2. [Installing Azure Ruby SDK](https://github.com/Azure/azure-sdk-for-ruby/wiki/Installing-Azure-Ruby-SDK)
 3. Using Azure Ruby SDK