Document the release process in RELEASE.rst

Fix #718

RELEASE.rst

@@ -0,0 +1,65 @@
+Releasing
+=========
+
+This describes for the maintainers of RGBDS how to publish a new release on
+GitHub.
+
+1. Update, commit, and push `include/version.h <include/version.h>`__ with
+   values for ``PACKAGE_VERSION_MAJOR``, ``PACKAGE_VERSION_MINOR``,
+   ``PACKAGE_VERSION_PATCH``, and ``PACKAGE_VERSION_RC``. Only define
+   ``PACKAGE_VERSION_RC`` if you are publishing a release candidate! You can
+   use ``git commit -m "Release <version>"`` and ``git push origin master``.
+
+2. Create a Git tag formatted as ``v<MAJOR>.<MINOR>.<PATCH>``, or
+   ``v<MAJOR>.<MINOR>.<PATCH>-rc<RC>`` for a release candidate. ``MAJOR``,
+   ``MINOR``, ``PATCH``, and ``RC`` should match their values from
+   `include/version.h <include/version.h>`__. You can use ``git tag <tag>``.
+
+3. Push the tag to GitHub. You can use ``git push origin <tag>``.
+
+   GitHub Actions will run the `create-release-artifacts.yaml
+   <.github/workflows/create-release-artifacts.yaml>`__ workflow to detect the
+   tag starting with "``v[0-9]``" and automatically do the following:
+
+   1. Build 32-bit and 64-bit RGBDS binaries for Windows with ``cmake``.
+
+   2. Package the binaries into zip files.
+
+   3. Package the source code into a tar.gz file with ``make dist``.
+
+   4. Create a draft GitHub release for the tag, attaching the three
+      packaged files. It will be a prerelease if the tag contains "``-rc``".
+
+      If an error occurred in the above steps, delete the tag and restart the
+      procedure. You can use ``git push --delete origin <tag>`` and
+      ``git tag --delete <tag>``.
+
+4. GitHub Actions will run the `create-release-docs.yml
+   <.github/workflows/create-release-docs.yml>`__ workflow to add the release
+   documentation to `rgbds-www <https://github.com/gbdev/rgbds-www>`__.
+
+   For a release candidate, which creates a prerelease, you will have to
+   take these steps yourself.
+
+   1. Clone `rgbds-www <https://github.com/gbdev/rgbds-www>`__. You can use
+      ``git clone https://github.com/gbdev/rgbds-www.git``.
+
+   2. Make sure that you have installed ``groff`` and ``mandoc``. You will
+      need ``mandoc`` 1.14.5 or later to support ``-O toc``.
+
+   3. Run ``.github/actions/get-pages.sh -r <path/to/rgbds-www> <tag>``. This
+      will render the RGBDS documentation as HTML and PDF and copy it to
+      ``rgbds-www``.
+
+      If you do not have ``groff`` installed, you can change
+      ``groff -Tpdf -mdoc -wall`` to ``mandoc -Tpdf -I os=Linux`` in
+      `.github/actions/get-pages.sh <.github/actions/get-pages.sh>`__ and it
+      will suffice.
+
+   4. Commit and push the documentation. You can use ``git commit -m
+      "Create RGBDS <tag> documentation"`` and ``git push origin master``
+      (within the ``rgbds-www`` directory, not RGBDS).
+
+5. Write a changelog in the GitHub draft release.
+
+6. Click the "Publish release" button to publish it!