xslt-sort.xhtml sort/@data-type corrected.

[XmlNirvana]

xslt-sort.xhtml - corrected the data-type attribute of the sort XSLT element. The corresponding part of the XSLT spec: https://www.w3.org/TR/1999/REC-xslt-19991116#sorting It says: <xsl:sort select = string-expression lang = { nmtoken } data-type = { "text" | "number" | qname-but-not-ncname } order = { "ascending" | "descending" } case-order = { "upper-first" | "lower-first" } />