Hi,
first of all, thanks for your tool that helps keeping API definitions and commits clean. ❤️

prettier has a CLI that makes it really easy to use it in scripts, e.g. in CI:

• --write replaces the input files
• it accepts (multiple) paths/glob patterns
• --check makes it fail if something changed

That might be a nice addition to openapi-format, too, although you can work arround the first two with find . -name '*.yaml' -exec yarn run openapi-format {} -o {} \;.