normalize announcements (#1784)

Author: bjohansebas

_data/en/general.yml

@@ -0,0 +1,2 @@
+title_announcement: "Express 5.0 documentation is now available."
+body_announcement: "The <a href='{{ page.lang }}/5x/api.html'>API documentation</a> is a work in progress.  For information on what's in the release, see the Express <a href='https://github.com/expressjs/express/blob/5.0/History.md'>release history</a>"

_includes/announcement.html

@@ -0,0 +1,9 @@
+<ul>
+    <li>
+      <p class="announcement-title">{% include icons/announcement.svg %} {{ site.data[page.lang].general.title_announcement }}</p>
+      <p markdown="1">
+        {{ site.data[page.lang].general.body_announcement }}
+      </p>
+    </li>
+</ul>
+