In introduction to Learn, mention where to find technical docs (graphql#128)

Author: leebyron

site/learn/Introduction.md

@@ -7,6 +7,8 @@ permalink: /learn/
 next: /learn/queries/
 ---
 
+> Learn about GraphQL, how it works, and how to use it in this series of articles. Looking for documentation on how to build a GraphQL service? There are libraries to help you implement GraphQL in [many different languages](/code/).
+
 GraphQL is a query language for your API, and a server-side runtime for executing queries by using a type system you define for your data. GraphQL isn't tied to any specific database or storage engine and is instead backed by your existing code and data.
 
 A GraphQL service is created by defining types and fields on those types, then providing functions for each field on each type. For example, a GraphQL service that tells us who the logged in user is (`me`) as well as that User's name might look something like this: