README.md in mainstreet-0.2.1 vs README.md in mainstreet-0.2.2

@@ -162,5 +162,14 @@
 
 - [Report bugs](https://github.com/ankane/mainstreet/issues)
 - Fix bugs and [submit pull requests](https://github.com/ankane/mainstreet/pulls)
 - Write, clarify, or fix documentation
 - Suggest or add new features
+
+To get started with development:
+
+```sh
+git clone https://github.com/ankane/mainstreet.git
+cd mainstreet
+bundle install
+bundle exec rake test
+```