Nested tables in DOCX are lost when converting to Markdown

Description:
When converting a DOCX file containing nested tables to Markdown using markitdown, the inner table content is discarded in the output. This occurs consistently with specific document structures.

Steps to Reproduce:

1. Environment:
   • Device: MacBook Pro with M3 chip

   • Installation:

   pip install -e 'packages/markitdown[all]'
   

2. Test File:
   • [Attach a minimal DOCX file with nested tables (e.g., outer table → inner table → text)].

3. Command:

   markitdown path-to-file.docx > document.md
   

4. Observed Result:
   • Outer table structure is preserved, but inner table content is missing in document.md.

5. Expected Result:
   • Both outer and inner tables should be rendered in Markdown (e.g., as nested HTML tables or flattened Markdown).

Start by reproducing the documented markitdown command with a DOCX containing an outer table, inner table, and text. Trace the DOCX-to-Markdown table conversion path; no source file or regression test is named in the issue. Done means inner-table content is preserved and a regression test covers the nested-table case.