Add books to Community-Resources.md (graphql#526)

* Add books to Community-Resources.md

* Add Elixir book

Author: lorensr

site/community/Community-Resources.md

@@ -96,6 +96,10 @@ Developers inside and outside of Facebook have given talks about GraphQL at conf
 
 ## Books
 
+- [The GraphQL Guide](https://graphql.guide) by John Resig and Loren Sands-Ramshaw
+- [Learning GraphQL](https://www.amazon.com/Learning-GraphQL-Declarative-Fetching-Modern/dp/1492030716/) by Eve Porcello and Alex Banks
+- [Fullstack GraphQL](https://www.graphql.college/fullstack-graphql) by Julian Mayorga
+- [Craft GraphQL APIs in Elixir with Absinthe](https://pragprog.com/book/wwgraphql/craft-graphql-apis-in-elixir-with-absinthe) by Bruce Williams and Ben Wilson
 - [Learning GraphQL and Relay](https://www.packtpub.com/web-development/learning-graphql-and-relay) by Samer Buna
 
 ## More Resources