DOC add bug fixes releases in News web section
<ul class="sk-landing-call-list list-unstyled">
<li><strong>On-going development:</strong>
<a href="https://scikit-learn.org/dev/whats_new.html"><strong>What's new</strong> (Changelog)</a>
+ <li><strong>April 2021.</strong> scikit-learn 0.24.2 is available for download (<a href="whats_new/v0.24.html#version-0-24-2">Changelog</a>).
+ </li>
+ <li><strong>January 2021.</strong> scikit-learn 0.24.1 is available for download (<a href="whats_new/v0.24.html#version-0-24-1">Changelog</a>).
+ </li>
<li><strong>December 2020.</strong> scikit-learn 0.24.0 is available for download (<a href="whats_new/v0.24.html#version-0-24-0">Changelog</a>).
</li>
<li><strong>August 2020.</strong> scikit-learn 0.23.2 is available for download (<a href="whats_new/v0.23.html#version-0-23-2">Changelog</a>).
