[Prettier Plugin] support placeholder (generic class attribute) for tailwindAttributes

[tpoisseau]

Hello,

Following the Contributing guide I firstly opened a discussion in June 2023 (and purpose to implement it myself).
https://github.com/tailwindlabs/tailwindcss/discussions/11410

But I didn't receive any response from staff and some users seems to wait for this feature, so I'm taking the liberty of opening an issue.

Best regards,