fix(ts): Query#first might return undefined

Author: leeyeh

storage.d.ts

@@ -543,7 +543,7 @@ export class Query<T extends Queriable> extends BaseQuery<T> {
   endsWith(key: string, suffix: string): this;
   equalTo(key: string, value: any): this;
   exists(key: string): this;
-  first(options?: AuthOptions): Promise<T>;
+  first(options?: AuthOptions): Promise<T | undefined>;
   get(objectId: string, options?: AuthOptions): Promise<T>;
   greaterThan(key: string, value: any): this;
   greaterThanOrEqualTo(key: string, value: any): this;
@@ -1170,6 +1170,7 @@ export function init(options: {
   appId: string;
   appKey: string;
   masterKey?: string;
+  hookKey?: string;
   region?: string;
   production?: boolean;
   serverURLs?: string | ServerURLs;