Fenced code in lists is malformed

[vasekbrychta]

Hello, I'm using fenced code inside lists and running prettifier malforms this fenced code blocks. It's indenting them as a code blocks that are not fenced, i.e. it adds one more level of indentation.

Before the prettifier runs:

After the prettifier runs:

Here's a gist with some good and bad examples of fenced code inside lists.

[vasekbrychta]

And now I noticed that it's adding backticks when run multiple times.

After running it twice from the original state I get this:

After running it for the third time, another backticks appear:

And so on...