Enhance structure and navigation of documentation

[jh-RLI]

Summary of the discussion

Enhance the documentation structure to add and provide information on technical (software modules & server structure) architecture, developement, collaboration and code documentation.

Type of change (CHANGELOG.md)

Updated

• Enhance documentation structure for development practice, code and architectural information (#1441)

Workflow checklist

Automation

Closes #1436

PR-Assignee

• [x] 🐙 Follow the workflow in CONTRIBUTING.md
• [x] 📝 Update the CHANGELOG.md
• [x] 📙 Update the documentation on mkdocs

Reviewer

• [ ] 🐙 Follow the Reviewer Guidelines
• [ ] 🐙 Provided feedback and show sufficient appreciation for the work done