Documenting the architecture of the project

Improve the documentation by understanding the current code and the Development.md file.
Please mention how the config based template rendering happens end-to-end.

Please add a flow diagram for ease of understanding.

Start by reading Development.md and the current code to trace how config-based template rendering works end to end. Document that flow and add a diagram showing the rendering path; the work is done when the architecture documentation explains the process clearly.

Written by the indexing model from the issue text.