Introduce @defer and @stream.

Update Section 3 -- Type System.md

Update Section 3 -- Type System.md

Update Section 3 -- Type System.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Update Section 6 -- Execution.md

Amend changes

Author: Keweiqu

spec/Section 3 -- Type System.md

@@ -697,8 +697,9 @@ And will yield the subset of each object type queried:
 When querying an Object, the resulting mapping of fields are conceptually
 ordered in the same order in which they were encountered during query execution,
 excluding fragments for which the type does not apply and fields or
-fragments that are skipped via `@skip` or `@include` directives. This ordering
-is correctly produced when using the {CollectFields()} algorithm.
+fragments that are skipped via `@skip` or `@include` directives or temporarily 
+skipped via `@defer`. This ordering is correctly produced when using the 
+{CollectFields()} algorithm.
 
 Response serialization formats capable of representing ordered maps should
 maintain this ordering. Serialization formats which can only represent unordered
@@ -1752,7 +1753,7 @@ A GraphQL schema describes directives which are used to annotate various parts
 of a GraphQL document as an indicator that they should be evaluated differently
 by a validator, executor, or client tool such as a code generator.
 
-GraphQL implementations should provide the `@skip` and `@include` directives.
+GraphQL implementations should provide the `@skip`, `@include`, `@defer` and `@stream` directives.
 
 GraphQL implementations that support the type system definition language must
 provide the `@deprecated` directive if representing deprecated portions of
@@ -1920,3 +1921,48 @@ type ExampleType {
   oldField: String @deprecated(reason: "Use `newField`.")
 }
 ```
+
+### @defer
+```graphql
+directive @defer(label: String!, if: Boolean) on FRAGMENT_SPREAD | INLINE_FRAGMENT
+```
+The `@defer` directive may be provided for fragment spreads and inline fragments to 
+inform the executor to delay the execution of the current fragment to indicate 
+deprioritization of the current fragment. A query with `@defer` directive will cause
+the request to potentially return multiple responses, where non-deferred data is 
+delivered in the initial response and data deferred delivered in a subsequent response.
+`@include` and `@skip` take presedence over `@defer`. 
+
+```graphql example
+query myQuery($shouldDefer: Boolean) {
+   user {
+     name
+     ...someFragment @defer(label: 'someLabel', if: $shouldDefer) 
+   }
+}
+fragment someFragment on User {
+  id
+  profile_picture {
+    uri
+  }
+}
+```
+
+### @stream
+```graphql
+directive @stream(label: String!, initial_count: Int!, if: Boolean) on FIELD
+```
+The `@stream` directive may be provided for a field of `List` type so that the 
+backend can leverage technology such asynchronous iterators to provide a partial
+list in the initial response, and additional list items in subsequent responses.
+`@include` and `@skip` take presedence over `@stream`.
+```graphql example
+query myQuery($shouldDefer: Boolean) {
+   user {
+     friends(first: 10) {
+       nodes @stream(label: "friendsStream", initial_count: 5)
+     }
+   }
+}
+
+```