Merge pull request #38670 from spowelljr/fixTabsCSS

Fix tabs shortcode CSS

Author: k8s-ci-robot

assets/scss/_base.scss

@@ -861,6 +861,10 @@ section#cncf {
 // nav-tabs and tab-content
 .nav-tabs {
   border-bottom: none !important;
+
+  .nav-item {
+    margin-bottom: 0;
+  }
 }
 
 .td-content .tab-content .highlight {