1. get_all_epub_files
Get all EPUB files in the specified directory.
2. get_metadata
Get metadata from an EPUB file.
3. get_toc
Get table of contents from an EPUB file.
4. get_chapter_markdown
Get chapter content in Markdown format from an EPUB file.
5. get_all_pdf_files
Get all PDF files in the specified directory.
6. get_pdf_metadata
Get metadata from a PDF file.
7. get_pdf_toc
Get table of contents from a PDF file.
8. get_pdf_page_text
Get plain text content from a specific page of a PDF file.
9. get_pdf_page_markdown
Get Markdown formatted content from a specific page of a PDF file.
10. get_pdf_chapter_content
Get chapter content and corresponding page numbers by chapter title from a PDF file.