Update README.md

Author: AuspeXeu

README.md

@@ -119,7 +119,7 @@ Requires bootstrap's dropdown component (`dropdowns.less`) for some styles, and
 A standalone .css file (including necessary dropdown styles and alternative, text-based arrows) can be generated by running `build/build_standalone.less` through the `lessc` compiler:
 
 ```bash
-$ lessc build/build_standalone.less datetimepicker.css
+$ lessc build/build_standalone.less > datetimepicker.css
 ```
 
 ## Options