docs: Enhance case study 01 notebook and update documentation

[AdemBoukhris457]

Description

This MR enhances the case study 01 financial report analysis notebook with improved display features and updates the documentation to include it in the notebooks table.

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Changes Made

Notebook Enhancements (notebooks/case_study_01_financial_report_analysis.ipynb)

• ✅ Add PDF pages display at the beginning (after Step 1)
• ✅ Display table descriptions from TOC alongside extracted dataframes
• ✅ Add Step 8 to display full markdown output from StructuredPDFParser
• ✅ Remove duplicate and empty cells
• ✅ Fix cell ordering (PDF display after Step 1, markdown display after Step 7)

Documentation Updates

• ✅ Add case study 01 to README.md Interactive Notebooks table
• ✅ Add case study 01 to English documentation (docs/en/index.md)
• ✅ Add case study 01 to Chinese documentation (docs/zh/index.md)

Testing

• Notebook cells execute correctly
• All markdown files render properly
• No linting errors
• Table formatting is correct in all three locations

Checklist

• Tests pass (N/A for documentation/notebook changes)
• Code formatted (N/A for markdown files)
• Documentation updated
• No breaking changes