Change order of set/from in example

Author: eKoopmans

README.md

@@ -98,7 +98,7 @@ var opt = {
 };
 
 // New Promise-based usage:
-html2pdf().from(element).set(opt).save();
+html2pdf().set(opt).from(element).save();
 
 // Old monolithic-style usage:
 html2pdf(element, opt);