message: Update docs/tools/rust.md with sampsyo suggestion
diff: @@ -25,6 +25,7 @@ Tools
  This library supports fully compatible Rust implementations of `bril2txt` and `bril2json`.
  For ease of use, these tools can be installed and added to your path by running the following in `bril-rs/`:
  +
  $ cargo install --path . --example bril2txt
  $ cargo install --path ./bril2json
  