better explanation and nicer formatting for the ssml reference test.

tests/ssml/references.ssml2

@@ -1,9 +1,9 @@
 <!-- SSML reference test
 Entity references &lt; &gt; &amp; &apos; and &quot; should be replaced in the buffer
-Character references &#65; are translated to Unicode (65 = 'A')
+Character references like &#65; are translated to Unicode (65 = 'A')
 
-See https://www.tutorialspoint.com/xml/xml_syntax.htm
+See https://www.tutorialspoint.com/xml/xml_syntax.htm for example
 -->
-<speak> &lt; &gt; &amp; &apos; &quot; </speak>
-<speak> B &#66;</speak>
+<speak>&lt; &gt; &amp; &apos; &quot;</speak>
+<speak>B &#66;</speak>
 <speak>z &#x7A;</speak>