update readme with GH pages link (#118)

Author: jjl014

README.md

@@ -4,6 +4,8 @@
 
 An iOS Client for [Constructor.io](http://constructor.io/).  [Constructor.io](http://constructor.io/) provides search as a service that optimizes results using artificial intelligence (including natural language processing, re-ranking to optimize for conversions, and user personalization).
 
+Full API documentation is available on [Github Pages](https://constructor-io.github.io/constructorio-client-swift/)
+
 ## 1. Import
 
 ### 1.a Import using CocoaPods