**Is your feature request related to a problem? Please describe.** For me, it's quite difficult at the moment to write custom lints for yaml files. To write a lint is possible, but I can't make the fixes work. It would be nice if the package could offer a simple solution for that, like with `DartLint` and `DartFix`. **Describe the solution you'd like** Add corresponding `YamlLint` and `YamlFix` class. **Describe alternatives you've considered** Add a guide on how to write linter rules for files others than dart.