fix(website): Link to correct release notes

The banner pointed to the 2.12.0 release notes. I changed the URL to go to the new release notes.

Author: guerda

website/docusaurus.config.js

@@ -105,7 +105,7 @@ const config = {
         ],
       },
       announcementBar: {
-        content: `⛰️ <b><a target="_blank" href="https://git-cliff.org/blog/2.12.0">git-cliff v2.13.0</a> is now out!</b> 🥳️`,
+        content: `⛰️ <b><a target="_blank" href="https://git-cliff.org/blog/2.13.0">git-cliff v2.13.0</a> is now out!</b> 🥳️`,
         backgroundColor: "#243840",
         textColor: "#ffffff",
         isCloseable: true,