Vouch request: Add danish translation

[carlvillads]

What do you want to change?

I'd like to contribute a new danish translation (da).

Why do you want to make this change?

I would like to use Ghostty on debian in danish, and be able to provide this experience for other users that want to do the same :)

I acknowledge that:

• I have read the Contributing Guide and understand the contribution process.
• I have read and agree to follow the AI Usage Policy.
• I wrote this vouch request myself, in my own voice, without AI generating it.

[pluiedev]

!vouch