docs: update adventure internationalization examples

[7rebux]

This pull request updates the Adventure Internationalization documentation to reflect recent changes in the API.

The current examples use TranslationRegistry, which has been deprecated and is scheduled for removal starting in version 4.20.0. To ensure compatibility with future versions of the Adventure library, the examples have been updated to use TranslationStore instead.

For more details on the deprecation, refer to the official documentation: TranslationRegistry.