message: Update release process for Cargo.
diff: @@ -137,12 +137,24 @@ Decide on a time to do the release, T.
  - [Hacker News](https://news.ycombinator.com/)
  - [Users forum](https://users.rust-lang.org/)
  -- **T+5m** - Tag Cargo the same way as rust-lang/rust and then run
  - `cargo publish` for the tag you just created. You'll first need to comment
  - out `cargo-test-macro` from Cargo.toml, then publish `crates-io` (in
  - `crates/crates-io`) and finally publish `cargo` itself.
  +- **T+5m** - Release and tag Cargo. In the rust-lang/rust repository on the
  + **stable branch**:
  - To publish Cargo you may have to bump the version numbers for the crates-io and Cargo crates; there's no need to do that in a formal commit though, so your tag and the published code may differentiate in that way.
  + ```sh
  + # Remote "rust-lang" is github.com/rust-lang/rust.git
  + git fetch rust-lang
  + git checkout rust-lang/stable
  + # Make sure submodules are at the correct revision.
  + git submodule update
  + cd src/tools/cargo
  + # Publish to crates.io. This will publish internal dependencies first (if
  + # necessary), then publish Cargo itself.
  + ./publish.py
  + # Where YY is the Rust minor release, add one to it (Rust 1.49.0 = Cargo 0.50.0).
  + CARGO_VERSION="0.YY+1.0"
  + git tag -u FA1BE5FE $CARGO_VERSION
  + git push git@github.com:rust-lang/cargo.git $CARGO_VERSION
  + ```
  - **T+1hr** Send a PR to the beta branch to comment out `dev: 1` again and
  update the date to download from (modifying `src/stage0.txt`).
  