[DOCS] aligning color code and adding prefix

Author: kadolor

docs-overrides/main.html

@@ -17,7 +17,7 @@
 
 {% block header %}
   <div style="background: #e25244; color: white; text-align: center; padding: 0.5rem;">
-    <a href="https://sedona.apache.org/sedonadb/" title="Announcement">📢 A single-node analytical database engine with geospatial as the first-class citizen.</a>
+    <a href="https://sedona.apache.org/sedonadb/" title="Announcement">📢 Introducing SedonaDB: A single-node analytical database engine with geospatial as the first-class citizen.</a>
   </div>
   {{ super() }} {# This renders the original header below your test bar #}
 {% endblock %}