Add missing release note link (#819)

Author: leofang

cuda_core/docs/source/release.rst

@@ -7,6 +7,7 @@ Release Notes
 .. toctree::
    :maxdepth: 3
 
+   release/0.3.2-notes
    release/0.3.1-notes
    release/0.3.0-notes
    release/0.2.0-notes