Broken link on Popup window (#6333)

Worth checking other pages as well

docs/maintain/archive/maintain-guides-democracy.md

@@ -11,7 +11,7 @@ import MessageBox from "../../../components/MessageBox"; import
 "../../../components/MessageBox.css";
 
 <MessageBox message="The content on this page is archived. For up-to-date information about governance, see the
-[Polkadot OpenGov page](../../learn/learn-polkadot-opengov.md)." />
+[Polkadot OpenGov page](../../learn/learn-polkadot-opengov)." />
 
 The public referenda chamber is one of the three bodies of on-chain governance as it's instantiated
 in Polkadot and Kusama. The other two bodies are the