[Mercure] Fix link to high-level implementations

Author: samnela

mercure.rst

@@ -532,7 +532,7 @@ its Mercure support.
 .. _`the Mercure protocol`: https://github.com/dunglas/mercure#protocol-specification
 .. _`Server-Sent Events (SSE)`: https://developer.mozilla.org/docs/Server-sent_events
 .. _`a polyfill`: https://github.com/Yaffle/EventSource
-.. _`high-level implementations`: https://github.com/dunglas/mercure#resources
+.. _`high-level implementations`: https://github.com/dunglas/mercure#tools
 .. _`In this recording`: https://www.youtube.com/watch?v=UI1l0JOjLeI
 .. _`API Platform`: https://api-platform.com
 .. _`Mercure.rocks`: https://mercure.rocks