docs: adjust source example

[StefanThoene]

Description

adjust source example with Constant and perequisites section

Issue linked

Checklist

• I have tested my changes locally.
• I have added necessary documentation or updated existing documentation.
• I have followed the coding style guidelines of this project.
• I have added appropriate tests (unit, integration, system).
• I have reviewed my changes before submitting this pull request.
• I have linked the issue or issues that are solved by the PR if any.
• I have assigned this PR to myself.
• I have made sure that the title of my PR follows Conventional commits style (e.g. feat: add optical property)
• I have agreed with the Contributor License Agreement (CLA).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.87%. Comparing base (a8036a6) to head (b8180bd).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #543   +/-   ##
=======================================
  Coverage   86.87%   86.87%           
=======================================
  Files          35       35           
  Lines        3840     3840           
=======================================
  Hits         3336     3336           
  Misses        504      504           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.