fix(markdown): handle CRLF correctly

[ikatyang]

Fixes #5413

We should figure out a better way to completely get rid of CRLF, but I think it needs more time since we don't want to break something like rangeFormat or cusorOffset.

• I’ve added tests to confirm my change works.
• (If changing the API or CLI) I’ve documented the changes I’ve made (in the docs/ directory)
• I’ve read the contributing guidelines.

✨Try the playground for this PR✨

[schallm]

Not sure if this should work (I have never used the playground before), but I tried the following markdown (small version of same issue we are currently seeing) in the playground:

- Option 1
    ```cmd
    dir c:\
    dir d:\
    ```

and received the following error in the output frame:

SyntaxError: Unexpected token, expected ";" (1:10)
> 1 | - Option 1
    |          ^
  2 |     ```cmd
  3 |     dir c:\
  4 |     dir d:\

[j-f1]

@schallm You have to select the markdown parser for it to work.