Improve LyntResult example

[saadq]

The "LyntResult example" in the API docs currently just shows this:

{
  filePath: string
  errors: Array<{
    ruleName: string
    message: string
    line: number
    column: number
    endLine?: number
    endColumn?: number
  }>
  errorCount: number
  fixCount: number
}

Instead of just having the type, it would be nice to show an actual example of what a LyntResult object might look like.