Heading following text without double line break does not get parsed

[EmilEriksen]

First of all thank you for creating this fantastic package! I'm having an issue with the following content:

# Heading
Naked content
# I'm not a heading :(

# Heading
<small>Content in small</small>
# I'm a heading!

The second heading does not seem to get parsed when there's only a single line break preceding it. It does work when there's some special content like an HTML-tag preceding it though. I think this is a bug. Other parsers render the second heading. It's also rendered here on Github:

Heading

Naked content

I'm not a heading :(

Heading 2

Content in small

I'm a heading!