The Markdown preview had a fixed 14px body and notebook Markdown cells inherited the UI font size, so enlarging them meant scaling the whole UI. Languages & Frameworks › Markdown › Preview font size (application-level, 8–72, following the editor font size until set) now drives the preview and notebook Markdown cells; fenced code scales with it, and notebook code cells and outputs follow the editor font.
Fixes#768
Co-authored-by: jaw52 <[email protected]>