Add "Rust-GB" (#251)

Author: zlfn

README.md

@@ -241,6 +241,7 @@ The [Choosing tools for Game Boy development](https://gbdev.io/guides/tools.html
 - [Assembler](https://github.com/ulrikdamm/Assembler) - Assembler written in Swift.
 - [llvm-gbz80](https://github.com/Bevinsky/llvm-gbz80) / [clang-gbz80](https://github.com/Bevinsky/clang-gbz80) - Clang/LLVM port to the GBZ80 CPU (similar to the deprecated [euclio/llvm-gbz80](https://github.com/euclio/llvm-gbz80)).
 - [gbdk-go](https://github.com/pokemium/gbdk-go) - A compiler translates Go programs to C code. The output C code is built into GB ROM by GBDK.
+- [Rust-GB](https://github.com/zlfn/rust-gb) - A compiler and library that enable the development of GB ROMs using Rust.
 
 ### Emulators