[FEATURE]: Add Persian (Farsi) docs site localization (fa locale)

[raminjafary]

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

#31771 covers the README in Farsi. This is the separate, larger piece: a full fa locale for the docs site (packages/web), which no existing issue or PR covers.