You could change:

  ```lisp
  foo
  ```

To

  ```
  foo
  ```

It would probably look better with no highlighting. The original arc tutorial was just a plain text file.

EDIT: Submitted a PR https://github.com/alephyud/bel/pull/5

You can see what it looks like here: https://github.com/shawwn/bel/blob/085b39f5b8ee9e50b9776972b...