Docs: Add gulp.series/gulp.parallel APIs, update gulp.task API & vinyl-fs options

Author: dinoboff

README.md

@@ -41,7 +41,7 @@ var paths = {
 };
 
 // Not all tasks need to use streams
-// A gulpfile is just another node program and you can use any package available on npm
+// A gulpfile is just another node program and you can use all packages available on npm
 gulp.task('clean', function() {
   // You can use multiple globbing patterns as you would with `gulp.src`
   return del(['build']);