docs: added deprecation note (#1188)

Author: dreamorosi

docs/overrides/main.html

@@ -5,4 +5,13 @@
 <a href="{{ '../' ~ base_url }}">
   <strong>Click here to go to latest.</strong>
 </a>
+{% endblock %}
+
+{% block announce %}
+Version 1.5.0 will be the last version to support Node.js 12. <br /> Node.js 12 has reached end-of-life and the
+corresponding
+AWS Lambda runtime will be deprecated at the end of March 2023. Please upgrade to Node.js 14 or later.<br />
+<a href="https://github.com/awslabs/aws-lambda-powertools-typescript/issues/1061#issuecomment-1349031362"
+  target="_blank">Click here to read the full announcement</a>, or <a href="https://discord.gg/B8zZKbbyET"
+  target="_blank">join our Discord server</a> to chime in the discussion.
 {% endblock %}