Update CHANGES.rst for new platforms.

CHANGES.rst

@@ -5,22 +5,36 @@
 3.1.0 (unreleased)
 ==================
 
+.. note::
+
+ This will be the last release to support Python 3.7 and 3.8.
+
 - Adds support for Python 3.13.
 
 .. note::
 
  greenlet will not work in no-gil (free threaded) builds of CPython.
  Internally, greenlet heavily depends on the GIL.
 
-.. note::
-
- This will be the last release to support Python 3.7 and 3.8.
-
 - Greatly reduce the chances for crashes during interpreter shutdown.
  See `issue 411
  <https://github.com/python-greenlet/greenlet/issues/411>`_.
-- Add untested support for Hitachi's SuperH CPU. This is not tested in
- CI. See `issue 166 <https://github.com/python-greenlet/greenlet/issues/166>`_.
+
+Platform Support
+----------------
+
+Support for the following platforms was contributed by the community.
+Note that they are untested by this project's continuous integration
+services.
+
+- Hitachi's `SuperH CPU <https://github.com/python-greenlet/greenlet/issues/166>`_.
+- `NetBSD on PowerPC.
+ <https://github.com/python-greenlet/greenlet/pull/402>`_
+- RiscV 64 with `-fno-omic-frame-pointer
+ <https://github.com/python-greenlet/greenlet/pull/404>`_. Note that
+ there are `known test failures
+ <https://github.com/python-greenlet/greenlet/issues/403>`_, so this
+ platform may not work reliably at all.
 
 
 3.0.3 (2023-12-21)