Update the docs to show tailwind v4 specific configs

[istiuak-0]

Themming and other sections of the docs still refer to the old Tailwind versions' configs (tailwind.config.ts) .

I think everyone is now pretty much moved to Tailwind v4.

So, it would be good to update the docs to Tailwind v4. it will be easier to follow then

[sadeghbarati]

#1515

Hi, here the v4 docs, only need Zernonia's approval