Parentheses errors when using more than one S-Expression

It seems that this project is used by GitHub and it shows syntax errors for code like this:


```scheme
(car (cons 1 2))
;; ==> 1
(cdr (cons 1 2))
;; ==> 2
(cadr (cons 1 (cons 2 3)))
```

This seems to happen when there is a comment:

```scheme
(car (cons 1 2))
(cdr (cons 1 2))
;; 
(cadr (cons 1 (cons 2 3)))
```