Document steps to release new versions

README.md

@@ -38,3 +38,16 @@ Several development commands are runnable with `make`:
 - `make check` does code formatting (checking, not modifying),
   linting, type checking, and testing in one command; if this command
   does not pass, CI will not pass
+
+## Releasing New Versions
+
+1. Increase the version in pyproject.toml.
+1. Add an entry for the new version in CHANGELOG.md.
+1. Tag the new version.
+   ```bash
+   $ git tag -s vVERSION COMMIT_SHA
+   ```
+1. Build the distribution.
+   ```bash
+   $ poetry build
+   ```