Add support for GraphQL (#2947)

* Add GraphQL to languages.yml

* Add graphql submodule

* Add graphql to grammars.yml

* Add GraphQL samples

* Updating licensed information

samples/GraphQL/kitchen-sink.graphql

@@ -0,0 +1,57 @@
+# Copyright (c) 2015, Facebook, Inc.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree. An additional grant
+# of patent rights can be found in the PATENTS file in the same directory.
+
+query queryName($foo: ComplexType, $site: Site = MOBILE) {
+  whoever123is: node(id: [123, 456]) {
+    id ,
+    ... on User @defer {
+      field2 {
+        id ,
+        alias: field1(first:10, after:$foo,) @include(if: $foo) {
+          id,
+          ...frag
+        }
+      }
+    }
+    ... @skip(unless: $foo) {
+      id
+    }
+    ... {
+      id
+    }
+  }
+}
+
+mutation likeStory {
+  like(story: 123) @defer {
+    story {
+      id
+    }
+  }
+}
+
+subscription StoryLikeSubscription($input: StoryLikeSubscribeInput) {
+  storyLikeSubscribe(input: $input) {
+    story {
+      likers {
+        count
+      }
+      likeSentence {
+        text
+      }
+    }
+  }
+}
+
+fragment frag on Friend {
+  foo(size: $size, bar: $b, obj: {key: "value"})
+}
+
+{
+  unnamed(truthy: true, falsey: false),
+  query
+}

samples/GraphQL/schema-kitchen-sink.graphql

@@ -0,0 +1,50 @@
+# Copyright (c) 2015, Facebook, Inc.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree. An additional grant
+# of patent rights can be found in the PATENTS file in the same directory.
+
+schema {
+  query: QueryType
+  mutation: MutationType
+}
+
+type Foo implements Bar {
+  one: Type
+  two(argument: InputType!): Type
+  three(argument: InputType, other: String): Int
+  four(argument: String = "string"): String
+  five(argument: [String] = ["string", "string"]): String
+  six(argument: InputType = {key: "value"}): Type
+}
+
+interface Bar {
+  one: Type
+  four(argument: String = "string"): String
+}
+
+union Feed = Story | Article | Advert
+
+scalar CustomScalar
+
+enum Site {
+  DESKTOP
+  MOBILE
+}
+
+input InputType {
+  key: String!
+  answer: Int = 42
+}
+
+extend type Foo {
+  seven(argument: [String]): Type
+}
+
+directive @skip(if: Boolean!) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT
+
+directive @include(if: Boolean!)
+  on FIELD
+   | FRAGMENT_SPREAD
+   | INLINE_FRAGMENT