Update README.md

Author: RadValentin

README.md

@@ -123,8 +123,8 @@ module: {
 - `prefix` - This string is added before every CSS selector.
 - `exclude` - It's possible to avoid prefixing some selectors by passing an array of selectors (strings or regular expressions).
 - `transform` - In cases where you may want to use the prefix differently for different selectors, it is possible to pass in a custom transform method.
-- `ignoreFiles` - List of ignored files for processing.
-- `includeFiles` - List of included files for processing.
+- `ignoreFiles` - List of ignored files for processing. Can be an array of file names or regex.
+- `includeFiles` - List of included files for processing.Can be an array of file names or regex.
 
 ## Maintainer