Update resources page to mention Codex (#509)

* Update resources page to mention Codex
   Rephrase for Codex, the design system
* Update links accordingly to latest

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Co-authored-by: Volker E <[email protected]>

resources.html

@@ -62,12 +62,17 @@ <h2>Components – WikimediaUI theme</h2>
 							<span class="resources-table__cell"></span>
 						</header>
 						<ul class="resources-table__body">
-							<li class="resources-table__cell">WikimediaUI components overview<br>&nbsp;<br>Sketch library features all WikimediaUI icons and colors as symbols as well and auto-notifications on official updates.</li>
+							<li class="resources-table__cell"><strong>WikimediaUI components overview</strong><br>&nbsp;<br>Sketch library features all WikimediaUI icons and colors as symbols as well and auto-notifications on official updates.</li>
 							<li class="resources-table__cell"><a class="lnk-resource" href="resources/WikimediaUI-components_overview.sketch" target="_blank" rel="noopener">Download Sketch</a><br>&nbsp;<br><a href="sketch://add-library?url=https%3A%2F%2Fdesign.wikimedia.org%2Fstyle-guide%2Fresources%2FWikimediaUI-components_overview-RSS.xml" rel="noopener">Import as Sketch library (RSS)</a></li>
 							<li class="resources-table__cell"><a class="lnk-resource" href="resources/WikimediaUI-components_overview.svg" target="_blank" rel="noopener">Download SVG</a></li>
 						</ul>
 						<ul class="resources-table__body">
-							<li class="resources-table__cell">OOUI (WikimediaUI theme) <br>OOUI is the main user-interface library of Wikimedia Foundation.</li>
+							<li class="resources-table__cell"><strong>Codex</strong><br>&nbsp;<br>Codex is the design system for Wikimedia – the successor of the Wikimedia Design Style Guide – and provides a toolkit for building user interfaces.</li>
+							<li class="resources-table__cell"><a href="https://doc.wikimedia.org/codex/latest/" target="_blank" rel="noopener">Demo &amp; Documentation</a></li>
+							<li class="resources-table__cell"><a href="https://github.com/wikimedia/codex" target="_blank" rel="noopener">Source Code</a></li>
+						</ul>
+						<ul class="resources-table__body">
+							<li class="resources-table__cell"><strong>OOUI (WikimediaUI theme)</strong><br>&nbsp;<br>OOUI is the legacy user-interface library of Wikimedia Foundation.</li>
 							<li class="resources-table__cell"><a href="https://doc.wikimedia.org/oojs-ui/master/demos/#widgets-mediawiki-vector-ltr" target="_blank" rel="noopener">Demo</a></li>
 							<li class="resources-table__cell"><a href="https://www.mediawiki.org/wiki/OOUI" target="_blank" rel="noopener">Documentation</a></li>
 						</ul>