Hi , can you add this in README? the url params issue in flying saucer

[JokerCatz]

first , sorry my poor English:)

the flying saucer has issue in params , like QR code image url in Google

http://chart.googleapis.com/chart?chs=50x50&cht=qr&chl=Hello+world&chld=L|1&choe=UTF-8

must change be

http://chart.googleapis.com/chart?chs=50x50&cht=qr&chl=Hello+world&chld=L|1&choe=UTF-8

"&" change to "&" , if not , will get error message of java , like this :

'The reference to entity "cht" must end with the ';' delimiter.'
Exception in thread "main" org.xhtmlrenderer.util.XRRuntimeException: Can't load the XML resource (using TRaX transformer). org.xml.sax.SAXParseException: The reference to entity "cht" must end with the ';' delimiter.

& it's can be helper(filter) to fix this issue :)