message: Tweak rustfmt details in CONTRIBUTING.md
  Closes
diff: @@ -81,10 +81,9 @@ of helpers to minimize boilerplate.
  installed locally, ignore the cross-compile test failures or disable them by
  using `CFG_DISABLE_CROSS_TESTS=1 cargo test`. Note that some tests are enabled
  only on `nightly` toolchain. If you can, test both toolchains.
  -* All code is expected to comply with the formatting suggested by `rustfmt`;
  -discrepancy is considered an error by CI, so a pull request with unsound
  -formatting will not be accepted. You can use `rustup component add rustfmt-preview`
  -to install `rustfmt` and use `cargo fmt` to automatically format your code.
  +* All code changes are expected to comply with the formatting suggested by `rustfmt`.
  +You can use `rustup component add rustfmt-preview` to install `rustfmt` and use
  +`cargo fmt` on the changed files to automatically format your code.
  * Push your commits to GitHub and create a pull request against Cargo's
  `master` branch.
  