refactor: enhance github url regex

[AndersDJohnson]

Description

Enhances the GitHub URL regex to only match issue URLs rather than any GitHub URL with digits in the path, to support multiple subdomains for some companies, to not limit supported domain and owner and repo names to basic A-Z character set but to support other ASCII or Unicode characters, etc. - all while retaining the fix from #86, mostly by using a [^\s] pattern to avoid matching whitespace.

Motivation and Context

There were some false positives and some cases where existing regex wouldn't quite work.

How Has This Been Tested?

• unit tests?

Existing unit tests pass. Added some more unit tests that fail without the changes but pass with.

Without changes:

With changes:

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Chore (updating repository quality of life, like deps, linting, etc.)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[therynamo]

😍 awesome! 🚀

These changes make way more sense. Regex... I tell ya 😄

Thank you for making a pr!