Hierarchical Rendering Support (Lists) for Deep Nesting

[leajalil]

Hello,
I've been using the Markdown exporter with complex SystemRDL files and have found that in some cases, a flat hierarchy is not desirable.

Having a nested hierarchy has the limitation that Markdown only supports one heading up to level 6.

Proposed Solution:

I've modified the exporter to support "Hierarchical" mode. In this mode:

• Containers (MapAddr, FileReg, Memory): Headings (#) are still used, dynamically increasing the depth.

• Records (Register): They are represented as list items (- Name) instead of headings.

• Fields: They are represented as nested list items (- Name).

This approach preserves the document structure boundary (saving headings for the actual containers) and provides a clearer visual hierarchy. I propose adding a configuration option (e.g., style='hierarchy' vs style='flat') to the export method to support this new rendering style while maintaining backward compatibility.