REL: 0.1

Update README, add CHANGES and RELEASING files

CHANGES.rst

@@ -0,0 +1,8 @@
+=========
+Changelog
+=========
+
+0.1 (2022-03-29)
+================
+
+* Initial public release

README.md

@@ -1,6 +1,9 @@
 # pycalphad-xml
 XML database plugin for PyCalphad
 
+This package (including the RelaxNG-based schemas that support it) are considered experimental and are likely to change.
+We welcome any feedback and encourage you to report issues or suggestions to us on our [GitHub issues page](https://github.com/pycalphad/pycalphad-xml/issues)!
+
 ## Installing
 
 ```shell
@@ -20,3 +23,12 @@ dbf = Database("my_db.xml")  # load from file
 
 dbf.to_file("out.xml")  # write to a file
 ```
+
+## Development versions
+
+To install the development version of `pycalphad-xml`, clone the repository and install it in editable mode with `pip`:
+
+```shell
+git clone git@github.com:pycalphad/pycalphad-xml.git
+pip install -e .
+```

RELEASING.rst

@@ -0,0 +1,52 @@
+Releasing pycalphad-xml
+=======================
+
+Create a release of pycalphad-xml
+---------------------------------
+To release a new version of pycalphad-xml:
+
+These steps assume that ``0.1`` is the most recently tagged version number and ``0.2`` is the next version number to be released.
+Replace their values with the last public release's version number and the new version number as appropriate.
+
+#. Determine what the next version number should be using `semantic versioning <https://semver.org/>`_.
+#. Resolve or defer all pull requests and issues tagged with the upcoming version milestone.
+#. ``git stash`` to save any uncommitted work.
+#. ``git checkout main``
+#. ``git pull`` to make sure you haven't missed any last-minute commits. **After this point, nothing else is making it into this version.**
+#. ``pytest`` to ensure that all tests pass locally.
+#. Update ``CHANGES.rst`` with a human-readable list of changes since the last commit.
+   ``git log --oneline --no-decorate --color 0.1^..main`` can be used to list the changes since the last version.
+#. ``git add CHANGES.rst`` to stage the updated documentation.
+#. ``git commit -m "REL: 0.2"`` to commit the changes.
+#. ``git push origin main``
+#. **Verify that all continuous integration test and build workflows pass.**
+#. Create a release on GitHub
+
+   #. Go to https://github.com/pycalphad/pycalphad-xml/releases/new
+   #. Set the "Tag version" field to ``0.2``.
+   #. Set the branch target to ``main``.
+   #. Set the "Release title" to ``pycalphad-xml 0.2``.
+   #. Leave the description box blank.
+   #. If this version is a pre-release, check the "This is a pre-release" box.
+   #. Click "Publish release".
+#. The new version will be available on PyPI when the ``Build and deploy to PyPI`` workflow on GitHub Actions finishes successfully.
+
+Deploy to PyPI (manually)
+-------------------------
+
+.. warning::
+
+   DO NOT FOLLOW THESE STEPS unless the GitHub Actions deployment workflow is broken.
+   Creating a GitHub release should trigger the ``Build and deploy to PyPI`` workflow on GitHub Actions that will upload source and platform-dependent wheel distributions automatically.
+
+To release a source distribution to PyPI:
+
+#. If deploying for the first time: ``pip install twine build``
+#. ``rm -R dist/*`` on Linux/OSX or ``del dist/*`` on Windows
+#. ``git checkout main`` to checkout the latest version
+#. ``git pull``
+#. ``git log`` to verify the repository state matches the newly created tag
+
+#. ``python -m build --sdist``
+#. **Make sure that the script correctly detected the new version exactly and not a dirty / revised state of the repo.**
+#. ``twine upload dist/*`` to upload (assumes a `correctly configured <https://packaging.python.org/specifications/pypirc/>`_ ``~/.pypirc`` file)