Update README.md (#636)

Author: SudoDios

README.md

@@ -60,6 +60,9 @@ A docker image is available on [GitHub](https://github.com/librespeed/speedtest/
 ## Go backend
 A Go implementation is available in the [`speedtest-go`](https://github.com/librespeed/speedtest-go) repo, maintained by [Maddie Zhan](https://github.com/maddie).
 
+## Rust backend
+A Rust implementation is available in the [`speedtest-rust`](https://github.com/librespeed/speedtest-rust) repo, maintained by [Sudo Dios](https://github.com/sudodios).
+
 ## Node.js backend
 A partial Node.js implementation is available in the `node` branch, developed by [dunklesToast](https://github.com/dunklesToast). It's not recommended to use at the moment.