readme.md in rubrowser-2.1.0 vs readme.md in rubrowser-2.2.0

@@ -50,9 +50,10 @@
 ## Usage
 
 
 ```
 Usage: rubrowser [options] [file] ...
+    -o, --output=FILE                output file page, if not specified output will be written to stdout
     -T, --no-toolbox                 Don't display toolbox on the page
     -v, --version                    Print Rubrowser version
     -h, --help                       Prints this help
 ```