docs: link to extension-registration in docs

Author: ReuDa

README.md

@@ -77,5 +77,5 @@ After installing, configure the extension by editing `/etc/steadybit/extension-i
 ## Extension registration
 
 Make sure that the extension is registered with the agent. In most cases this is done automatically. Please refer to
-the [documentation](https://docs.steadybit.com/install-and-configure/install-agent/extension-discovery) for more
+the [documentation](https://docs.steadybit.com/install-and-configure/install-agent/extension-registration) for more
 information about extension registration and how to verify.