Update README.md

Author: Federico Moyá

README.md

@@ -13,6 +13,16 @@ Depending on your `SimpleCoV`'s settings you will experiment different outcomes.
 - If you configure `SimpleCov` to run with `branch` coverage you should expect an output formatted like [sample_with_branch.json](https://github.com/fede-moya/simplecov_json_formatter/blob/master/spec/fixtures/sample_with_branch.json)
 - Otherwise you should expect an output formatted like [sample.json](https://github.com/fede-moya/simplecov_json_formatter/blob/master/spec/fixtures/sample.json)
 
+## Development
+
+We encourage you to use docker for common operations like running tests, or debugging your code. Running `make sh` will run a new container instance based on the `Dockerfile` provided at root, finally a shell prompt will be displayed on your terminal. Also, syncronization with your local files will be already set. 
+### Tests
+`make test` will trigger the excution of both running tests and running rubocop as linter a check, by simply running `rake`, this actions will be run inside a new container but using your local files.
+
+### Format
+
+`make format` will run `rubocop -a` which stands for _autocorrect_ and format your code according to the `.rubocop.yml` config file. 
+
 ## Copyright
 
 See License ?