Add instructions to CONTRIBUTING

Author: brunoocasali

CONTRIBUTING.md

@@ -34,12 +34,11 @@ You can set up your local environment natively or using `docker`, check out the
 
 Example of running all the checks with docker:
 ```bash
-docker-compose run --rm package bash -c "list of the commands required to build + run tests + run linters"
+docker-compose run --rm package bash -c "swift test && swift run swiftlint"
 ```
 
 To install dependencies:
 
-
 ```bash
 swift build
 ```
@@ -72,19 +71,7 @@ If you want to fix your linting errors:
 swift run swiftlint --fix
 ```
 
-### On Xcode <!-- omit in TOC -->
-
-### Setup <!-- omit in TOC -->
-
-You can set up your local environment natively or using `docker`, check out the [`docker-compose.yml`](/docker-compose.yml).
-
-Example of running all the checks with docker:
-```bash
-docker-compose run --rm package bash -c "list of the commands required to build + run tests + run linters"
-```
-
-To install dependencies:
-
+### Setup on Xcode <!-- omit in TOC -->
 
 To build the project, if it's not already done, click on the play button in the top left corner of Xcode.