Minor tweak of a doc comment for ItemizedBlock::new.

Author: Lukasz Anforowicz

src/comment.rs

@@ -490,8 +490,8 @@ impl ItemizedBlock {
         None // No markers found.
     }
 
-    /// Creates a new ItemizedBlock described with the given `line`
-    /// or None if `line` doesn't start an item.
+    /// Creates a new `ItemizedBlock` described with the given `line`.
+    /// Returns `None` if `line` doesn't start an item.
     fn new(line: &str) -> Option<ItemizedBlock> {
         let marker_length = ItemizedBlock::get_marker_length(line.trim_start())?;
         let space_to_marker = line.chars().take_while(|c| c.is_whitespace()).count();