Add release instructions

docs/src/contributing.md

@@ -56,3 +56,38 @@ Incremental autobuild is also supported:
 ```bash
 make docs-serve
 ```
+
+## Maintainers: release process
+
+**Pre-release steps**
+
+1. Make sure that all tests pass.
+2. Make sure the change log is up-to-date. Add the release date to the relevant
+   section header.
+3. Set the package version number to the target value:
+
+   ```bash
+   rye version <MAJOR.MINOR.PATCH>
+   ```
+
+4. Create and push a commit with the following message:
+   `dessinemoi version <MAJOR.MINOR.PATCH>`.
+
+**Release steps**
+
+1. Create a [new release on GitHub](https://github.com/rayference/dessinemoi/releases>).
+2. When asked for a tag, create a new one (`v<MAJOR.MINOR.PATCH>`).
+3. The automated workflow will build the package and upload it to PyPI.
+
+**Post-release steps**
+
+1. Create a new section in the change log (`whats_new.md`) with the title
+   *Dessine-moi <MAJOR.MINOR.PATCH> (upcoming release)*.
+2. Bump the version to the next development one:
+
+   ```bash
+   rye version <MAJOR.MINOR.PATCH>.dev
+   ```
+
+3. Create and push a commit with the following message:
+   `Version <MAJOR.MINOR.PATCH> ready for development`.