Add Exclusion Names for Rule file-name-casing

[rwaskiewicz]

PR checklist

• Addresses an existing issue: fixes Exclusion options for file-name-casing #4050
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

• Add exclusion option for one or more files
• Add test files

Is there anything you'd like reviewers to focus on?

N/A

[ulrichb]

@rwaskiewicz Could you maybe solve the merge conflict (or give me write access to your fork, so I could do it)?

[JoshuaKGoldberg]

Hey @rwaskiewicz, just a heads up - the file-name-casing rule had some pretty merge-conflict-y changes in the interim, including allowing an options object to apply a different casing preference per file name regexp matcher. That makes solving #4050 a bit easier! Added an "ignored" option to exclude file names.

[JoshuaKGoldberg]

...and we're merged! Sorry it took so long, and thanks to @rwaskiewicz for getting this started! The "ignored" option will be available in the next TSLint release.