Feature Request: Option to have images scale to window

Hello! Currently, if a large image is in a document, it extends beyond the size of the window when rendered, making then hard to see. An option to keep images wider than current window to be rendered within the margins would improve rendered readability.

The issue names no file, test, or entry point. Begin by locating where rendered Markdown images are sized relative to the window, then verify that an option keeps oversized images within the margins without changing smaller images.

Written by the indexing model from the issue text.