Changed --test to take multiple directories

[JoshuaKGoldberg]

PR checklist

• Addresses an existing issue: Allow --test against a glob pattern of directories #2064
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

What changes did you make?

Used an extra glob.sync to allow for wildcards / general glob patterns from --test.

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

A couple of issues I think should be addressed before merge:

• No tests added. I didn't see much coverage for runTest other than the CLI's general exit code testing. I can add exit similar testing for runTests, but is there a more direct testing method you'd like instead?
• Can part of ruleTestRunner.ts be replaced with runTests?

[nchen63]

looks good, thanks!

[JoshuaKGoldberg]

Thanks for the quick merge @nchen63! About the extra points in the PR - I'll look into doing both of those as described unless directed otherwise.

[nchen63]

Yep, those are both fine. Make sure all changes to ruleTestsRunner are backwards compatible