Bracket characters in the alt text are backslash-escaped so the rendered link stays a single
image node when re-parsed. A href containing whitespace is angle-wrapped, the form markdown
requires for such hrefs; data URIs never contain whitespace and pass through unwrapped.
Parameters
alt: string|undefined
Alt text, or undefined for empty brackets
href: string
The href, typically a data URI or a filesystem path
Render an image link in standard markdown syntax.
Bracket characters in the alt text are backslash-escaped so the rendered link stays a single image node when re-parsed. A href containing whitespace is angle-wrapped, the form markdown requires for such hrefs; data URIs never contain whitespace and pass through unwrapped.