Slides not generated correctly when using numbered lists in markdown file

[John Wadleigh]

Hi there! Thanks for the cool product. I tried running it with the following command line options (using headers as slide breakup).

markdown-to-slides README.md -o slideshow.html -d

In my markdown file I have the following.

## Test header
This is an example

1. test
    ```
    code example
    ```
2. two
    ```
    some code example
    ```
3. thi
    ```
    more code
    ```

## another header
test

This causes a problem in the generated html. The resulting html slides never breaks on the following header marker.