[MINOR] No need to jump to web pages (#4994)

Co-authored-by: zhongjingxiong <zhongjingxiong@bytedance.com>

README.md

@@ -74,6 +74,6 @@ There is more information in the [contributing] guide.
 [flight-readme]: arrow-flight/README.md
 [datafusion-readme]: https://github.com/apache/arrow-datafusion/blob/master/README.md
 [ballista-readme]: https://github.com/apache/arrow-ballista/blob/master/README.md
-[objectstore-readme]: https://github.com/apache/arrow-rs/blob/master/object_store/README.md
+[objectstore-readme]: object_store/README.md
 [issues]: https://github.com/apache/arrow-rs/issues
 [discussions]: https://github.com/apache/arrow-rs/discussions