chore(doc/contributing): replace the deprecated Wiki tutorial link by the jenkins.io doc one

[lemeurherve]

This PR updates the Jenkins plugin tutorial link.

• [x] Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• [x] Ensure that the pull request title represents the desired changelog entry
• [x] Please describe what you did
• [x] Link to relevant issues in GitHub or Jira
• [x] Link to relevant pull requests, esp. upstream and downstream changes
• [x] Ensure you have provided tests - that demonstrates feature works or fixes the issue