Update the description in example.md

src/xslt/example.md

@@ -1,5 +1,6 @@
-origin xml
+This XML code block is an example of file we process.
 
+```xml
 <root>
   <result>
     <biographic_references/>
@@ -14,11 +15,11 @@ origin xml
     </contributors>
   </result>
 </root>
+```
 
+With the XSLT code block below, we can transform the upper XML block into a new XML file.
 
-XSLT file
-
-
+```xslt
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:foo="http://www.foo.org/" xmlns:bar="http://www.bar.org">
 <xsl:template match="/">
@@ -34,4 +35,15 @@ XSLT file
 </oai_zb_preview>
 </xsl:template>
 </xsl:stylesheet>
+```
+This transformation outputs the result below.
+```xml
+<oai_zb_preview xmlns:foo="http://www.foo.org/" xmlns:bar="http://www.bar.org">
+   <author>Maynard, James</author>
+   <author_ids>
+      <author_id>maynard.james</author_id>
+   </author_ids>
+</oai_zb_preview>
+```
+