Merge pull request #3268 from bdarnell/main-branch-relnotes

Copy version 6.3.2 release notes to main branch

docs/releases.rst

@@ -4,6 +4,7 @@ Release notes
 .. toctree::
    :maxdepth: 2
 
+   releases/v6.3.2
    releases/v6.3.1
    releases/v6.3.0
    releases/v6.2.0

docs/releases/v6.3.2.rst

+What's new in Tornado 6.3.2
+===========================
+
+May 13, 2023
+------------
+
+Security improvements
+~~~~~~~~~~~~~~~~~~~~~
+
+- Fixed an open redirect vulnerability in StaticFileHandler under certain
+  configurations.
\ No newline at end of file