Clarify release process / workflow

Author: grega

README.md

@@ -103,6 +103,8 @@ git tag v0.x.0
 git push origin v0.x.0
 ```
 
+The `release` workflow will automatically build and publish a new release to GitHub when the tag is pushed.
+
 2. Get the sha256 of the release tarball:
 
 ```bash