libxmljs: add missing parserOption (#40599)
libxmljs: add missing parserOption (#40599)

libxmljs: Added missing parser option for baseUrl (used by parseXml and parseHtml).
dsebastien/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped,mcliment/DefinitelyTyped,georgemarshall/DefinitelyTyped