Backport PR pandas-dev#43046: DOC: Start v1.3.3 release notes (pandas-dev#43055)

Co-authored-by: Simon Hawkins <[email protected]>

Author: meeseeksmachine

doc/source/whatsnew/index.rst

@@ -16,6 +16,7 @@ Version 1.3
 .. toctree::
    :maxdepth: 2
 
+   v1.3.3
    v1.3.2
    v1.3.1
    v1.3.0

doc/source/whatsnew/v1.3.2.rst

@@ -47,4 +47,4 @@ Bug fixes
 Contributors
 ~~~~~~~~~~~~
 
-.. contributors:: v1.3.1..v1.3.2|HEAD
+.. contributors:: v1.3.1..v1.3.2

doc/source/whatsnew/v1.3.3.rst

@@ -0,0 +1,45 @@
+.. _whatsnew_133:
+
+What's new in 1.3.3 (September ??, 2021)
+----------------------------------------
+
+These are the changes in pandas 1.3.3. See :ref:`release` for a full changelog
+including other versions of pandas.
+
+{{ header }}
+
+.. ---------------------------------------------------------------------------
+
+.. _whatsnew_133.regressions:
+
+Fixed regressions
+~~~~~~~~~~~~~~~~~
+-
+-
+
+.. ---------------------------------------------------------------------------
+
+.. _whatsnew_133.bug_fixes:
+
+Bug fixes
+~~~~~~~~~
+-
+-
+
+.. ---------------------------------------------------------------------------
+
+.. _whatsnew_133.other:
+
+Other
+~~~~~
+-
+-
+
+.. ---------------------------------------------------------------------------
+
+.. _whatsnew_133.contributors:
+
+Contributors
+~~~~~~~~~~~~
+
+.. contributors:: v1.3.2..v1.3.3|HEAD