Like "gofmt" for Go, we ought to have a "promfmt" for Prometheus since we have a syntax tree. The idea being that the system produces uniform style that minimizes deviation and learning curve.

Update after we have totally moved to YAML rule files: In addition to formatting the PromQL expressions, we also want to format the YAML files to have a fixed structure, while preserving comments for both PromQL expressions and the YAML file.