Update changelog.

CHANGES.rst

@@ -5,11 +5,39 @@ Cython Changelog
 3.0.0 alpha 6 (2020-0?-??)
 ==========================
 
+Features added
+--------------
+
+* No/single argument functions now accept keyword arguments by default in order
+  to comply with Python semantics.  The marginally faster calling conventions
+  ``METH_NOARGS`` and ``METH_O`` that reject keyword arguments are still available
+  with the directive ``@cython.always_allow_keywords(False)``.
+  (Github issue #3090)
+
+* A low-level inline function ``total_seconds(timedelta)`` was added to
+  ``cpython.datetime`` to bypass the Python method call.  Note that this function
+  is not guaranteed to give exactly the same results for very large time intervals.
+  Patch by Brock Mendel.  (Github issue #3616)
+
+* Type inference now understands that ``a, *b = x`` assigns a list to ``b``.
+
 Bugs fixed
 ----------
 
-* Single argument functions did not accept keyword arguments.
-  (Github issue #3090)
+* Includes all bug-fixes from the 0.29.19 release.
+
+Other changes
+-------------
+
+* The ``numpy`` declarations were updated.
+  Patch by Brock Mendel.  (Github issue #3630)
+
+* The names of Cython's internal types (functions, generator, coroutine, etc.)
+  are now qualified with the module name of the internal Cython module that is
+  used for sharing them across Cython implemented modules, for example
+  ``_cython_3_0a5.coroutine``.  This was done to avoid making them look like
+  homeless builtins, to help with debugging, and in order to avoid a CPython
+  warning according to https://bugs.python.org/issue20204
 
 
 3.0.0 alpha 5 (2020-05-19)