Add documentation on how to create a changelog entry

docs/developer-guide.txt

@@ -57,6 +57,38 @@ Setuptools makes extensive use of hyperlinks to tickets in the changelog so
 that system integrators and other users can get a quick summary, but then
 jump to the in-depth discussion about any subject referenced.
 
+---------------------
+Making a pull request
+---------------------
+
+When making a pull request, please include a short summary of the changes
+and a reference to any issue tickets that the PR is intended to solve. All
+PRs with code changes should include tests. All changes should include a
+changelog entry.
+
+``setuptools`` uses `towncrier <https://town-crier.readthedocs.io/en/latest/>`_
+for changelog managment, so when making a PR, please add a news fragment in the
+``changelog.d/`` folder. Changelog files are written in Restructured Text and
+should be a 1 or 2 sentence description of the substantive changes in the PR.
+They should be named ``<pr_number>.<category>.rst``, where the categories are:
+
+- ``change``: Any backwards compatible code change
+- ``breaking``: Any backwards-compatibility breaking change
+- ``doc``: A change to the documentation
+- ``misc``: Changes internal to the repo like CI, test and build changes
+- ``deprecation``: For deprecations of an existing feature of behavior
+
+A pull request may have more than one of these components, for example a code
+change may introduce a new feature that deprecates an old feature, in which
+case two fragments should be added. It is not necessary to make a separate
+documentation fragment for documentation changes accompanying the relevant
+code changes. See the following for an example news fragment:
+
+.. code-block:: bash
+
+    $ cat changelog.d/1288.change.rst
+    Add support for maintainer in PKG-INFO
+
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 Source Code
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