Headers are not handled well when combined with details/summary tags

[alexei-osipov]

h3 results in badly formatted output when combined with details/summary tags

This code

from bs4 import BeautifulSoup
from markdownify import MarkdownConverter

sample = """
<details><summary>Some question text</summary><div><h3>Answer</h3> Answer text</div></details>
"""

soup = BeautifulSoup(sample, 'html.parser')
result = MarkdownConverter().convert_soup(soup)
print(result)

Actual result (on 0.12.1):

Some question text### Answer

 Answer text

Expected result:

Some question text

### Answer

Answer text

[jsm28]

PR #120 should help here, it fixes various cases of block tags not being properly separated from adjacent content, including headers.