README.md in jekyll-zopfli-2.0.0 vs README.md in jekyll-zopfli-2.1.0

@@ -63,10 +63,12 @@
 
 `Jekyll::Zopfli` only runs when the environment variable `JEKYLL_ENV` is set to `production` as dealing with gzipping files is unnecessary in development mode and just slows down the site build.
 
 ### Configuration
 
+#### Extensions
+
 By default, `Jekyll::Zopfli` will compress all files with the following extensions:
 
 - '.html'
 - '.css'
 - '.js'
@@ -84,9 +86,18 @@
 zopfli:
   extensions:
     - '.html'
     - '.css'
     - '.js
+```
+
+#### Replacing the original file
+
+If you host your Jekyll site on AWS S3 you can take advantage of `Jekyll::Zopfli` for compressing the whole site. The only difference is that you need to replace the uncompressed file with the gzipped file (that is, without a `.gz` extension). To enable this in `Jekyll::Zopfli` turn the `replace_files` setting to `true`.
+
+```yml
+zopfli:
+  replace_files: true
 ```
 
 ### Serving pre-compiled gzip files
 
 You will likely need to adjust your web server config to serve these precomputed gzip files. See below for common server configurations: