Add links to free edX course

This commit adds a few links to the free GraphQL edX course.

Signed-off-by: Brian Warner <[email protected]>

Author: brianwarner

site/community/Community-Resources.md

@@ -114,6 +114,7 @@ Developers inside and outside of Facebook have given talks about GraphQL at conf
 
 To explore other community-developed resources and content about GraphQL, take a look at these sites:
 
+- [Exploring GraphQL: A Query Language For APIs](https://www.edx.org/course/exploring-graphql-a-query-language-for-apis): A free 7 week edX course
 - [How to GraphQL](https://www.howtographql.com): The Fullstack Tutorial for GraphQL
 - [Building Apollo](https://dev-blog.apollodata.com/)
 - [Learn GraphQL](https://learngraphql.com/basics/introduction)

site/learn/Introduction.md

@@ -7,7 +7,7 @@ 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/). For an in-depth learning experience with practical tutorials, visit the [How to GraphQL](https://www.howtographql.com) fullstack tutorial website.
+> 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/). For an in-depth learning experience with practical tutorials, visit the [How to GraphQL](https://www.howtographql.com) fullstack tutorial website. We have also partnered with edX to create a free online course, [Exploring GraphQL: A Query Language for APIs](https://www.edx.org/course/exploring-graphql-a-query-language-for-apis).
 
 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.