let sqlite add extensions

storage/sqlite/sqlite.html

@@ -77,6 +77,8 @@
     be sure to include $ on the parameter object key.</p>
     <p>Using any SQL Query, the result is returned in <code>msg.payload</code></p>
     <p>Typically the returned payload will be an array of the result rows, (or an error).</p>
+    <p>You can load sqlite extensions by inputting a <code>msg.extension</code> property containing the full
+    path and filename.</p>
     <p>The reconnect timeout in milliseconds can be changed by adding a line to <b>settings.js</b>
     <pre>sqliteReconnectTime: 20000,</pre></p>
 </script>