Fix headings that are separated by only one newline 🚧

Previously the following lead to only one line with both heading and body:
```
# Heading
Body
```

1 files changed, 1 insertions, 0 deletions

diff --git a/src/eval/mod.rs b/src/eval/mod.rs
index 4cfebd3e..e1682adc 100644
--- a/src/eval/mod.rs
+++ b/src/eval/mod.rs
@@ -357,6 +357,7 @@ impl Eval for NodeHeading {
         ctx.state.font.strong = true;
 
         self.contents.eval(ctx);
+        SynNode::Parbreak.eval(ctx);
 
         ctx.state = prev;
     }