Update docs/configuring-playbook-bridge-mautrix-signal.md: add a link to the official documentation on authentication

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-playbook-bridge-mautrix-signal.md

@@ -55,4 +55,4 @@ ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,ensure-matrix-use
 
 To use the bridge, you need to start a chat with `@signalbot:example.com` (where `example.com` is your base domain, not the `matrix.` domain).
 
-You can learn more here about authentication from the bridge's [official documentation on Authentication](https://docs.mau.fi/bridges/go/signal/authentication.html).
+You can then follow instructions on the bridge's [official documentation on Authentication](https://docs.mau.fi/bridges/go/signal/authentication.html).