Add RELEASING.md

Author: dmartin

RELEASING.md

@@ -0,0 +1,12 @@
+# Releasing
+
+1. Ensure that [`CHANGELOG.md`](./CHANGELOG.md) is up-to-date with all relevant changes. Additionally, make sure that the version specified in [Cargo.toml](./Cargo.toml) matches the to-be-released version.
+
+1. Create and push a new Git tag for the version with a `v` prefix, e.g.:
+    ```shell
+    git tag vX.Y.Z
+    git push --tags
+    ```
+    This will automatically run the "Publish release" GitHub Actions workflow, which will create a GitHub release, build a release tarball, and attach the tarball to the release.
+
+1. Edit the newly created GitHub release, setting the relevant section of `CHANGELOG.md` as the description.