This diff replaces the lint engine to override the linter paths to run
on. Only the first path is kept so the linter will effectively run once.
To do so the linter should define the `shouldRunOnce` method (and return
true). This is achieved by extending the `GlobalExternalLinter` class
and implementing the `parseGlobalLinterOutput` method. The `check-doc`
linter is the first to benefit this feature.