Correct broken link

Author: fisuda

README.md

@@ -74,7 +74,7 @@ same name: `CSRF_COOKIE_AGE`, `CSRF_COOKIE_HTTPONLY`, `CSRF_COOKIE_NAME`,
 `CSRF_COOKIE_SECURE`, `EMAIL_HOST`, `EMAIL_HOST_PASSWORD`, `EMAIL_PORT`,
 `EMAIL_HOST_USER`, `EMAIL_USE_SSL`, `EMAIL_USE_TLS`, `SECRET_KEY`,
 `SESSION_COOKIE_AGE`, `SESSION_COOKIE_NAME`, `SESSION_COOKIE_HTTPONLY` and
-`SESSION_COOKIE_SECURE`. See [Django documentation](DJANGO_SETTINGS) for more
+`SESSION_COOKIE_SECURE`. See [Django documentation][DJANGO_SETTINGS] for more
 details.
 
 When running WireCloud with TLS behind a reverse proxy such as Apache/NGINX