fix(jmx): minor typo

Author: yamahito

src/main/xar-resources/data/jmx/jmx.xml

@@ -36,7 +36,7 @@
 
     <sect1 xml:id="monitoring">
         <title>Monitoring and Management</title>
-        <para>This sections explains how to monitor an eXist instance using common Java tools.</para>
+        <para>This section explains how to monitor an eXist instance using common Java tools.</para>