feat: multiple locales on multiple domains

[DarthGigi]

🔗 Linked issue

#1161

❓ Type of change

• 📖 Documentation (updates to the documentation, readme or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Resolves #1161 by allowing the same locale on multiple domains. Eg:

NL domain:
https://mydomain.nl/ -> https://mydomain.nl/ (nl language)
https://mydomain.nl/en -> https://mydomain.nl/en (en language)
https://mydomain.nl/de -> https://mydomain.nl/de (de language)

https://mydomain.nl/nl -> https://mydomain.nl/nl (404)

DE domain:
https://mydomain.de/ -> https://mydomain.nl/ (nl language)
https://mydomain.de/en -> https://mydomain.nl/en (en language)
https://mydomain.de/nl -> https://mydomain.nl/de (de language)

https://mydomain.de/de -> https://mydomain.de/de (404)

📝 Checklist

• I have linked an issue or discussion.
• I have added tests (if possible).
• I have updated the documentation accordingly.

[DarthGigi]

I've fixed the tests, all tests should pass now. Documentation has been added as well.