Add temporary note about preview release to index.html

index.html

@@ -447,6 +447,18 @@
         >the article</a>.
     </p>
 
+    <p>
+      <i><a
+   href="https://cdn.rawgit.com/jashkenas/underscore/node-native-esm/index.html"
+      >Prerelease version 1.13.0-0</a> adds full support for native ESM
+      imports in Node.js version 12 and later. It should do this without
+      breaking existing setups. Please try it out by installing
+      <tt>underscore@preview</tt> from NPM and let us know whether it worked
+      for you in <a
+        href="https://github.com/jashkenas/underscore/pull/2914"
+      >the pull request</a>!</i>
+    </p>
+
     <p>
       Enjoying Underscore, and want to <i>turn it up to 11?</i> Try <a href="https://documentcloud.github.io/underscore-contrib/">Underscore-contrib</a>.
     </p>