Add support for more languages

[zolakt]

Checklist

• [X] I have filled out the template to the best of my ability.
• [X] This only contains 1 feature request (if you have multiple feature requests, open one feature request for each feature request).
• [X] This issue is not a duplicate feature request of previous feature requests.

Is your feature request related to a problem? Please describe.

Your project is available only for assistants in these languages: ["en", "de", "pl", "es", "it", "fr", "pt", "hi"] Otherwise it appears as disabled, and can't be used. I don't see why all of them couldn't be added to this list, since it just makes robot sounds anyway.

Describe the solution you'd like

For my use case, at least support Croatian (ISO "hr")

Describe alternatives you've considered

No real alternatives. The only option I have is to use English for the whole Assistant, but that is not what I want.

Additional context

Here is the code: https://github.com/vigonotion/tts.astromech/blob/81286b37eb5c9bea42824a29e04308441211ce46/custom_components/astromech/tts.py#L76