Add defer/stream tutorial

Author: robrichard

website/docs/tutorials/defer-stream.md

@@ -0,0 +1,26 @@
+---
+title: Enabling Defer & Stream
+sidebar_label: Enabling Defer & Stream
+---
+
+The `@defer` and `@stream` directives are not enabled by default. In order to use these directives, you must add them to your GraphQL Schema.
+
+```js
+import {
+  GraphQLSchema,
+  GraphQLDeferDirective,
+  GraphQLStreamDirective,
+  specifiedDirectives,
+} from 'graphql';
+
+const schema = new GraphQLSchema({
+  query,
+  directives: [
+    ...specifiedDirectives,
+    GraphQLDeferDirective,
+    GraphQLStreamDirective,
+  ],
+});
+```
+
+If the `directives` option is passed to `GraphQLSchema`, the default directives will not be included. `specifiedDirectives` must be passed to ensure all standard directives are added in addition to `defer` & `stream`.

website/sidebars.js

@@ -16,5 +16,6 @@ module.exports = {
       items: ['tutorials/constructing-types'],
     },
     'tutorials/express-graphql',
+    'tutorials/defer-stream',
   ],
 };