fix(ts): Update typings to allow additional DocumentNode (#78)

Author: FredyC

index.d.ts

@@ -1,4 +1,4 @@
 import { DocumentNode } from 'graphql';
 
 export function loader(path: string): DocumentNode;
-export function gql(taggedTemplateLiteral: TemplateStringsArray): DocumentNode;
+export function gql(taggedTemplateLiteral: TemplateStringsArray, ...nodes: DocumentNode[]): DocumentNode;