Fix link to "Partner websites"

Author: Hans5958

src/content/docs/Useful related, informational sites.mdx

@@ -9,7 +9,7 @@ This page lists official and unofficial Vocaloid/voice synthesizer related websi
 
 Commonly used music related stores and commercial websites can also be found here.
 
-See our [partner websites](/docs/vocadb-partner-websites).
+See our [partner websites](/docs/partner-websites).
 
 ---