message: Add a link to the GitHub SoR board
diff: @@ -5,7 +5,8 @@ title: State Of Rust
  This document is intended to document the current state of Rust's various
  unstable features, their current status and what's required next to
  -be completed.
  +be completed. It should be kept in sync with the
  +[State of Rust](https://github.com/rust-lang/rust/projects/8) board.
  | Team | Feature | Status | What's next | Last update |
  | ---- | ------- | ------ | ----------- | ----------- |
  