docs(contributing): code from another PR removed, correct code added

.github/CONTRIBUTING.md

@@ -1,10 +1,12 @@
+Sure, here's the adapted markdown code using GitLab Flow:
+
 # Contributing Rules
 
 - The development will be done **in English**.
 - Commit messages **must** follow
 [Conventional Commits specifications](https://www.conventionalcommits.org/en/v1.0.0/#specification).
 - Branches **must** follow the
-[Git Flow pattern](https://github.com/nvie/gitflow).
+[GitLab Flow pattern](https://docs.gitlab.com/ee/topics/gitlab_flow.html).
 - Versioning must follow the
 [Semantic Versioning specifications](https://semver.org/).
 - Every contribution **must** be accompanied by a test suite that tests the new
@@ -28,28 +30,22 @@ response was given then the issue will be closed.
 
 ## Starting
 
-This guide assumes you have
-[Git Flow](https://github.com/nvie/gitflow/wiki/Installation) installed on your
-system. The `main` branch is **always** the production branch, and the
-`develop` branch is **always** the development branch.
+This guide assumes you have [GitLab Flow pattern](https://docs.gitlab.com/ee/topics/gitlab_flow.html) installed on your system. The `main` branch is **always** the production branch.
 
 To create a feature/bugfix branch, use the command:
 
 ```sh
-git flow feature start <feature-name>
+git checkout -b <feature-name> main
 # or
-git flow bugfix start <bugfix-name>
+git checkout -b <bugfix-name> main
 ```
 
-Git Flow will automatically create and checkout the branch, make the changes in
-your favorite code editor. When you're done with the changes, commit and use
-the following command to publish the feature on GitHub:
+Git will automatically create and checkout the branch, make the changes in your favorite code editor. When you're done with the changes, commit and use the following command to publish the feature on GitLab:
 
 ```sh
-git flow feature publish <feature-name>
+git push origin <feature-name>
 # or
-git flow bugfix publish <bugfix-name>
+git push origin <bugfix-name>
 ```
 
-The branch should automatically be published on GitHub. Wait a supervisor to
-review your code and merge or request changes if necessary.
+The branch should automatically be published on GitLab. Wait a supervisor to review your code and merge or request changes if necessary.