maint: update RELEASING now that version is computed from a tag (#187)

## Which problem is this PR solving?

- Followup to #186 to correct the releasing steps.

RELEASING.md

@@ -1,12 +1,11 @@
 # Releasing
 
-- Update version number in `main.go`
-- Update `CHANGELOG.md` with the changes since the last release. Consider automating with a command such as these two:
+- Update `CHANGELOG.md` with the changes since the last release. Consider automating with a command such as one of these two:
   - `git log $(git describe --tags --abbrev=0)..HEAD --no-merges --oneline > new-in-this-release.log`
   - `git log --pretty='%C(green)%d%Creset- %s | [%an](https://github.com/)'`
 - Commit changes, push, and open a release preparation pull request for review.
 - Once the pull request is merged, fetch the updated `main` branch.
-- Apply a tag for the new version on the merged commit (e.g. `git tag -a v0.1.0-alpha -m "v0.1.0-alpha"`)
+- Apply an annotated tag (`git tag -a`) for the new version on the merged commit (e.g. `git tag -a v0.1.0-alpha -m "v0.1.0-alpha"`)
 - Push the tag upstream (this will kick off the release pipeline in CI) e.g. `git push origin v0.1.0-alpha`
 - Ensure that there is a draft GitHub release created as part of CI publish steps.
 - Click "generate release notes" in GitHub for full changelog notes and any new contributors