Point the MDD card at its docs site

Assisted-by: Claude:claude-opus-5

Co-Authored-By: lsimons-bot <bot@leosimons.com>

Author: lsimons

docs/src/content/docs/index.mdx

@@ -90,7 +90,7 @@ elsewhere:
 				time, in the smallest grammar that can carry them.
 			</Card>
 		</a>
-		<a class="card-link" href="https://github.com/schubergphilis/mdd">
+		<a class="card-link" href="https://schubergphilis.github.io/mdd/">
 			<Card title="MDD">
 				Markdown Does Docs. Bidirectional sync between markdown-in-git and
 				Confluence, SharePoint and Office, around one typed document IR.