Adding banner

Author: leandrodamascena

docs/overrides/main.html

@@ -1,5 +1,10 @@
 {% extends "base.html" %}
 
+{% block announce %}
+<p>🚨 As of February 8, 2024, AWS Lambda will no longer allow Python 3.7 functions to be updated. Inline with this, Powertools releases will stop supporting it.</p>
+<p>Please ensure you update your functions to Python 3.8 or later to continue to use the latest version of Powertools for AWS Lambda (Python).</p>
+{% endblock %}
+
 {% block outdated %}
   You're not viewing the latest version.
   <a href="{{ '../' ~ base_url }}">