This section provides an example of formatting an XML file to a PDF file with XSLT stylesheets.
In the previous two examples, the input file is an XSL-FO file which contains
the source information mixed with the XSL formatting objects directly. In this example,
the source information is stored in an normal XML file, and the XSL formatting
objects are mixed with the XSL transformation templates in an XSL file.
So I modified the old hello.xsl into hello_fo.xsl: