Comments don't work with headings

[mrlogick]

I think that this code

{%
# title

paragraph
%}

should produce nothing.

Instead, it produces:

<p>{%
# title</p>
<p>paragraph
%}</p>

So, it's not possible to comment the headings and the paragraphs too in oneshot, without multiple inline comments?

[hellux]

Unfortunately it is currently not possible to have blank lines within comments, so one cannot easily comment out a big block if it contains blank lines using djot comments.

The reference implementation (https://github.com/jgm/djot.js) has the same behavior, which I have mimicked. There have been discussions about ways to add better block comments for djot in jgm/djot#67.

One workaround is to use raw blocks for a nonexistent render output, e.g. "comment":

```=comment
# title

paragraph
```

This will be cause the whole raw block to be filtered out by the renderer.