message: add docs for `cargo miri`
diff: @@ -47,6 +47,13 @@ environment variable to `trace`. These traces are indented based on call stack
  depth. You can get a much less verbose set of information with other logging
  levels such as `warn`.
  +## Running miri on your own project('s test suite)
  +
  +Install miri as a cargo subcommand with `cargo install --debug`.
  +Then, inside your own project, use `cargo +nightly miri` to run your project, if it is
  +a bin project, or run `cargo +nightly miri test` to run all tests in your project
  +through miri.
  +
  ## Contributing and getting help
  Check out the issues on this GitHub repository for some ideas. There's lots that
  