Merge pull request #133 from davidjb/patch-1

Clarify which optimisers are enabled by default

Author: tcoopman

README.md

@@ -83,7 +83,7 @@ loaders: [{
 }]
 ```
 
-Comes bundled with the following optimizers:
+Comes bundled with the following optimizers, which are automatically enabled by default:
 
 - [mozjpeg](https://github.com/imagemin/imagemin-mozjpeg) — *Compress JPEG images*
 - [optipng](https://github.com/kevva/imagemin-optipng) — *Compress PNG images*