toy/image_optim

# Contributing

* Create topic/feature branch: `git checkout -b awesome-changes`
* Commit…
* Add an entry at the top (after ## unreleased) of [ChangeLog](CHANGELOG.markdown), include:
  * Issues (`[#123](https://github.com/toy/image_optim/issues/123)`)
  * Pull requests (`[#123](https://github.com/toy/image_optim/pull/123)`)
  * Authors (`[@octocat](https://github.com/octocat)`)
* Run tests: `bundle exec rspec`
* Check code style: `bundle exec rubocop`
* Rebase on master and squash commits to logical units
* Push your branch: `git push origin awesome-changes`
* Create pull request
* Check if [github actions workflow is happy](https://github.com/toy/image_optim_pack/actions/workflows/check.yml)