message: doc: Fix crates URL in README
  Fixes
diff: @@ -94,7 +94,7 @@ from being requires.
  ## Usage
  To use Buttplug in your rust application or library, check out the
  -[buttplug package on crates.io](https://crates.io/buttplug).
  +[buttplug package on crates.io](https://crates.io/crates/buttplug).
  The following crate features are available
  