message: docs(ember): Mention `tracesSampleRate` in Ember docs
  This should help new users get started faster by including what is needed for performance right away.
diff: @@ -27,11 +27,11 @@ Then add the following config to `config/environment.js`
  ```javascript
  ENV['@sentry/ember'] = {
  sentry: {
  - dsn: '__DSN__' // replace __DSN__ with your DSN
  + dsn: '__DSN__' // replace __DSN__ with your DSN,
  + tracesSampleRate: 1.0, // Be sure to lower this for your production environment
  }
  };
  ```
  -
  ### Usage
  To use this SDK, call `InitSentryForEmber` before the application is initialized, in `app.js`. This will load Sentry config from `environment.js` for you.
  @@ -74,6 +74,7 @@ Aside from configuration passed from this addon into `@sentry/browser` via the `
  };
  ```
  +
  ### Performance
  #### Routes
  If you would like to capture `beforeModel`, `model`, `afterModel` and `setupController` times for one of your routes,
  