Merge pull request #23 from braun-embedded/release-procedure

Document release procedure

Author: hannobraun

CONTRIBUTING.md

@@ -16,3 +16,57 @@ This repository contains multiple crates: The main `step-dir` crate, as well as
 This means if a new version of `step-dir` is released, all driver crates are released around the same time, sharing the same version number. Updating the versions will be done in the same commit, and that commit will be tagged with the version number for that release.
 
 If a new release of some, but not all, crates is required, the version of all other crates is still updated, and a release is published. This is not ideal, but it prevents a situation where a crate must skip a version number, which could be confusing. Such a situation can occur because each release is tagged in the repository, and we can't create multiple tags for the same version number (and if we could, we really shouldn't).
+
+### Publishing a release
+
+This procedure should really be automated, but for now it is at least documented.
+
+1. Make sure your local `master` branch is up-to-date:
+
+```
+git switch master
+git pull --rebase
+```
+
+2. Choose new version number, according to [Semantic Versioning]. The following steps will use `a.b.c` as a placeholder for the chosen version.
+
+3. Create a release branch (replace `a.b.c` with actual version)
+
+```
+git switch -c publish-a.b.c
+```
+
+4. Update changelog: Go through all pull requests since the last release and mention the relevant ones. Use changelog entries as the template. Commit this to the repository.
+
+5. Update versions in all `Cargo.toml` files, including dependencies on `step-dir` in drivers. Commit this to the repository.
+
+6. Push branch, open a pull request. This makes sure the CI runs and gives other maintainers a chance to weigh in.
+
+7. Once ready, publish `step-dir`: Run `cargo publish` from the repository root.
+
+8. Publish all driver crates. Go into each directory in `drivers/`, run `cargo publish` there.
+
+9. Tag the release
+
+```
+git tag va.b.c
+```
+
+10. Merge pull request, clean up your local branch.
+
+```
+# merge pull request
+git switch master
+git pull --rebase
+git remote prune origin
+git branch -d publish-a.b.c
+```
+
+11. Push the release tag
+
+```
+git push --tag
+```
+
+
+[Semantic Versioning]: https://semver.org/