Render an existing Markdown (.md) file on disk as a cleanly styled PDF using a headless Chromium engine. Use this whenever the user has a Markdown file they want as a PDF — for example notes, READMEs, reports, or documentation. Output supports: GitHub Flavored Markdown tables, syntax-highlighted fenced code blocks (highlight.js), headings H1–H6, ordered/unordered/nested lists, blockquotes, horizontal rules, links, and images scaled to page width. Page size, margins, and footer page numbers are configurable. Returns the absolute path of the written PDF on success.

Render a Markdown string directly to a styled PDF without needing a source .md file on disk. Use this when the Markdown content lives in the current conversation — for example, content you have just generated, pasted-in text, or a transformation of another document. Supports the same Markdown features as `convert_file_to_pdf` (GFM tables, syntax-highlighted code, headings, lists, blockquotes, images, links) and the same page/margin/footer options. Returns the absolute path of the written PDF on success.