Add a link for the WiP "New features with Apache 2.5/2.6" page
[skip ci]
Documentation</title>
<category id="release"><title>Release Notes</title>
+ <page href="new_features_2_6.html">New features with Apache 2.5/2.6</page>
<page href="new_features_2_4.html">New features with Apache 2.3/2.4</page>
<page href="new_features_2_2.html">New features with Apache 2.1/2.2</page>
<page href="new_features_2_0.html">New features with Apache 2.0</page>
