Merge pull request #7 from browserstack/readme-update

Updated README with link to Parallel Test Calculator

Author: sinstein

README.md

@@ -11,8 +11,10 @@
 
 ## Running your tests
 * To run a single test, run `composer single`
-* To run parallel tests, run `composer parallel`
 * To run local tests, run `composer local`
+* To run parallel tests, run `composer parallel`
+
+ Understand how many parallel sessions you need by using our [Parallel Test Calculator](https://www.browserstack.com/automate/parallel-calculator?ref=github)
 
 ## Notes
 * You can view your test results on the [BrowserStack Automate dashboard](https://www.browserstack.com/automate)