message: minor update to Slide Number name
diff: @@ -703,7 +703,7 @@ function slideObjectToXml(slide: PresSlide | SlideLayout): string {
  strSlideXml +=
  '<p:sp>' +
  ' <p:nvSpPr>' +
  - ' <p:cNvPr id="25" name="Slide Number Placeholder 24"/>' +
  + ' <p:cNvPr id="25" name="Slide Number Placeholder 0"/>' +
  ' <p:cNvSpPr><a:spLocks noGrp="1"/></p:cNvSpPr>' +
  ' <p:nvPr><p:ph type="sldNum" sz="quarter" idx="4294967295"/></p:nvPr>' +
  ' </p:nvSpPr>' +
  