message: add link to Rust's installation guide
diff: @@ -41,7 +41,7 @@ the HermitCore kernel and applications you need:
  * Netwide Assember (NASM)
  * recent host compiler such as GCC
  * HermitCore cross-toolchain, i.e. Binutils, GCC, newlib, pthreads
  - * Rust compiler
  + * [Rust compiler (nightly release)](https://www.rust-lang.org/en-US/install.html)
  ### HermitCore cross-toolchain
  