Initial commit

This includes a rough port of the data types at
https://github.com/graphql/graphql-js/blob/master/src/language/ast.js

README.md

@@ -0,0 +1,22 @@
+# Haskell GraphQL
+
+[![Hackage Version](https://img.shields.io/hackage/v/graphql.svg)](https://hackage.haskell.org/package/graphql)
+
+For now this only provides the data types to represent the GraphQL AST,
+but the idea is to be a Haskell port of
+[`graphql-js`](https://github.com/graphql/graphql-js). Next releases
+should include:
+
+- [ ] Parser for the GraphQL language.
+- [ ] Data types for the GraphQL Schema language.
+- [ ] Parser for the GraphQL Schema language.
+- [ ] Interpreter of GraphQL requests.
+- [ ] Utilities to define GraphQL types and schema.
+
+## Contact
+
+Suggestions, contributions and bug reports are welcome.
+
+Feel free to contact me, jdnavarro, on the #haskell channel on the
+[GraphQL Slack Server](https://graphql.slack.com). You can obtain an
+invitation [here](https://graphql-slack.herokuapp.com/).