Issue with rendering whitespace to commonmark

[bbelay-ptc]

There is an issue with cmark_render_commonmark function when it gets as an input a document that has a text node with a whitespace in the beginning, it does not return a correct markdown string.

For example, the following document:
Document node -> Paragraph node -> Text node with text literal
is rendered as text\n, which is a code block.

From looking at some other implementation I see the whitespace is replaced with  . Can this applied in cmark? thanks