fix: watch() can abbreviate opt

gulp/gulp.d.ts

@@ -241,6 +241,15 @@ declare module gulp {
         dest(outFolder:(file:string)=>string, opt?:IDestOptions): NodeJS.ReadWriteStream;
 
 
+        /**
+         * Watch files and do something when a file changes. This always returns an EventEmitter that emits change events.
+         *
+         * @param glob a single glob or array of globs that indicate which files to watch for changes.
+         * @param tasks names of task(s) to run when a file changes, added with gulp.task()
+         */
+        watch(glob:string, tasks:string[]): EventEmitter;
+        watch(glob:string[], tasks:string[]): EventEmitter;
+
         /**
          * Watch files and do something when a file changes. This always returns an EventEmitter that emits change events.
          *