message: generalize readme
diff: @@ -61,8 +61,8 @@ rustup component add miri
  If `rustup` says the `miri` component is unavailable, that's because not all
  nightly releases come with all tools. Check out
  [this website](https://rust-lang.github.io/rustup-components-history) to
  -determine a nightly version that comes with Miri and install that, e.g. using
  -`rustup install nightly-2019-03-28`.
  +determine a nightly version that comes with Miri and install that using
  +`rustup install nightly-YYYY-MM-DD`.
  Now you can run your project in Miri:
  