update README.md

Author: paramonovav

README.md

@@ -17,6 +17,12 @@ Go to your Spress site and add the following to your `composer.json` and run
 
 ### How to use?
 
+Add the following to your config.yml to exclude some files from minify/compress process:
+
+```yaml
+html_compress_exclude: ['.htaccess','robots.txt','crossdomain.xml', 'sitemap.xml','nortonsw_bc7be3d0-796e-0.html','BingSiteAuth.xml']
+```
+
 Just run build command:
 
 ```bash