Is your feature request related to a problem? Please describe.
In order to use this formatter in a git pre-commit hook (which also works with partial staging), I need the console tool to write the results to stdout instead of modifying the original file.

Describe the solution you'd like

1. There's a command line option that writes the formatted document to stdout instead of modifying the file. The option is mutually exclusive with --passive.
2. When the option is enabled, the tool doesn't log to stdout anymore, but to stderr.