Use OptionResolver for `.doctor-rst.yaml` file

[alamirault]

We have a lot of exclusions in phpstan-baseline.neon and some \assert(...) in code

Using OptionResolver for $config will add a better UX and better validation

https://github.com/OskarStark/doctor-rst/blob/01e1ce5346c233b89d861e082d32bcffbd200648/src/Command/AnalyzeCommand.php#L91