bug: incremental edit removes necessary escape character

[vezwork]

When dragging anything within the kanban (see demos quartohub project), this:

::: {.kanban}

## todo

* Don't give up
* Do everything necessary

## doing

* splorin\'

## ok this exists

- other stuff!

:::

Gets rewritten to:

::: {.kanban}

## todo

* Don't give up

## doing

* splorin'

## okthisexists

* other stuff!
* Do everything necessary

:::

Note the resulting lack of escaped single quote \' on * splorin'. This breaks the subsequent parse.

[cscheid]

Is this a bug on our markdown writer more directly? There might be some subtlety on canonicalization of apostrophes (quotes are real syntax in Markdown, on account of the Quoted node...)