DOC update index showing new release
<li><strong>On-going development:</strong>
<a href="https://scikit-learn.org/dev/whats_new.html"><strong>What's new</strong> (Changelog)</a>
</li>
+ <li><strong>October 2022.</strong> scikit-learn 1.1.3 is available for download (<a href="whats_new/v1.1.html#version-1-1-3">Changelog</a>).
+ </li>
<li><strong>August 2022.</strong> scikit-learn 1.1.2 is available for download (<a href="whats_new/v1.1.html#version-1-1-2">Changelog</a>).
</li>
<li><strong>May 2022.</strong> scikit-learn 1.1.1 is available for download (<a href="whats_new/v1.1.html#version-1-1-1">Changelog</a>).
