Minor: Reduce indirection for finding changlog (apache#13199)

* Minor: Improve changelog links

* revert changelog

Author: alamb

CHANGELOG.md

@@ -17,6 +17,7 @@
   under the License.
 -->
 
-* [DataFusion CHANGELOG](./datafusion/CHANGELOG.md)
+Change logs for each release can be found [here](dev/changelog).
+
 
 For older versions, see [apache/arrow/CHANGELOG.md](https://github.com/apache/arrow/blob/master/CHANGELOG.md).