message: say where the rust-timer bot command docs are
diff: @@ -82,6 +82,9 @@ necessary try-build and queue a perf run by saying
  (Technically, the requirement is that the `queue` command finishes executing prior
  to the try build completing successfully.)
  +See the [documentation](https://github.com/rust-lang/rustc-perf/tree/master/collector#benchmarking)
  +for further bot commands.
  +
  [collector]: https://github.com/rust-lang-nursery/rustc-perf/tree/master/collector
  [web frontend + bot]: https://github.com/rust-lang-nursery/rustc-perf/tree/master/site
  