docs: Fix link to official docs in README (#1117)

Author: ywuenthought

README.md

@@ -88,7 +88,7 @@ curl http://127.0.0.1:8088/api/recommend/bob?n=10
 
 For more information：
 
-- Read [official documents](https://gorse.io/docs/master)
+- Read [official documents](https://gorse.io/docs/)
 - Visit [official demo](https://gitrec.gorse.io/)
 - Discuss on [Discord](https://discord.gg/x6gAtNNkAE) or [GitHub Discussion](https://github.com/gorse-io/gorse/discussions)