Adding v2 maintainance mode banner

Author: leandrodamascena

docs/overrides/main.html

@@ -1,5 +1,12 @@
 {% extends "base.html" %}
 
+{% block announce %}
+On March 25st, 2025 v2 of Powertools for AWS Lambda (Python) <a
+  href="https://github.com/aws-powertools/powertools-lambda-python/issues/5239" target="_blank">will reach
+  End-of-Life</a>. We recommend you to <a href="https://docs.powertools.aws.dev/lambda/python/latest/upgrade/"
+  target="_blank">upgrade to v3</a>.
+{% endblock %}
+
 {% block outdated %}
   You're not viewing the latest version.
   <a href="{{ '../' ~ base_url }}">