docs(homepage): set url for end-of-support in announce block (#1893)

Author: LuisValdesZero

docs/overrides/main.html

@@ -2,7 +2,7 @@
 
 {% block announce %}
 👋 Powertools for Python v1 will no longer receive updates or releases after 31/03/2023!
-We encourage you to read our <a href="/upgrade/#end-of-support-v1">upgrade guide on how to migrate to v2</a>.
+We encourage you to read our <a href="{{ base_url }}/upgrade/#end-of-support-v1">upgrade guide on how to migrate to v2</a>.
 {% endblock %}
 
 {% block outdated %}