Keep emphasis when creating block quotes

[wheelercj]

Stardown's "Copy markdown of selection" option doesn't keep italicization/emphasis with the setting "when creating markdown of a selection, create a block quote and a page title link".

For example, the selection shown in this photo:

results in this markdown:

Italicized text is the cat’s meow.

— Basic Syntax | Markdown Guide

It should result in this markdown:

Italicized text is the cat’s meow.

— Basic Syntax | Markdown Guide

Further nesting of block quotes should also work.