Fix reference to non-existent "example three" (php#5724)

* [skip-revcheck] Fix reference to non-existent "example three"

The short tags paragraph referred to "example three", but the page
only has a single <example> block containing three manually numbered
code snippets, not three separate examples. Point to the third line
of that example instead.

Closes php#5685

Co-authored-by: Jordi Kroon <jordikroon@php.net>

Author: GabrielCordeiroBarrosoTeles

language/basic-syntax.xml

@@ -40,12 +40,12 @@
     </example>
    </para>
 
-   <para>
-    Short tags (example three) are available by default but can be disabled
+   <simpara>
+    Short tags (the third line in the example above) are available by default but can be disabled
     either via the <link linkend="ini.short-open-tag">short_open_tag</link>
     &php.ini; configuration file directive, or are disabled by default if
     PHP is built with the <option>--disable-short-tags</option> configuration.
-   </para>
+   </simpara>
    <para>
     <note>
      <para>