Add standalone scrollable card pattern

index.html

@@ -43,6 +43,7 @@
         <li><a href="./patterns/portal-header.html">Portal Header</a></li>
         <li><a href="./patterns/options-row.html">Options Row</a></li>
         <li><a href="./patterns/object-card.html">Object Card</a></li>
+        <li><a href="./patterns/scrollable-card.html">Scrollable Card</a></li>
         <li><a href="./patterns/object-group-card.html">Object Group Card</a></li>
         <li><a href="./patterns/navigation-card.html">Navigation Card</a></li>
         <li><a href="./patterns/left-navigation.html">Left Navigation</a></li>