Code improvement

- [x] Enable [SwiftFormat](https://github.com/nicklockwood/SwiftFormat)
- [ ] Store.voiceRate be changed as Float
- [ ] Check builds in pre-commit hook

[SwiftLint SwiftFormat Danger Sourcery SwiftGen and Git Hook](https://artsy.github.io/blog/2019/01/05/its-time-to-use-spm/)