Removes code blocks in markdown unless then are separated

Test to Markdown problem:

```
### test1

### test2

### test3
```

will be updated to (even if test1, test2 and test3 exist)
to

```
### test3
test3 code block
```

Have to separate individual functions using `---` like this

```
### test1

---
### test2

---
### test3
```

Reproduce the Markdown transformation shown in the issue, comparing adjacent headings with and without `---` separators. Trace the JavaScript documentation-generation path that performs this conversion and identify the relevant parser or rendering tests. Done means the three existing sections and their code blocks remain present without requiring separators.

Written by the indexing model from the issue text.