Update appendix-06-translation.md - new persian translation added (#4192

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as I mentioned in my translation issue, I have mostly completed a translation of the Rust Book into Persian (Chapters 0 to 16) and still working on the complete chapters. While a previous translation exists, it only covers the first three or four chapters and remains incomplete.

Co-authored-by: Chris Krycho <[email protected]>

src/appendix-06-translation.md

@@ -21,7 +21,7 @@ For resources in languages other than English. Most are still in progress; see
 - [Esperanto](https://github.com/psychoslave/Rust-libro)
 - [ελληνική](https://github.com/TChatzigiannakis/rust-book-greek)
 - [Svenska](https://github.com/sebras/book)
-- [Farsi](https://github.com/RustFarsi/book)
+- [Farsi](https://github.com/RustFarsi/book), [Persian (FA)](https://github.com/persian-rust/book)
 - [Deutsch](https://github.com/rust-lang-de/rustbook-de)
 - [हिंदी](https://github.com/venkatarun95/rust-book-hindi)
 - [ไทย](https://github.com/rust-lang-th/book-th)