Move trailing whitespace parsing to a separate element.

I still need to parse the line break at the end of elements.

src/parser/util.rs

@@ -77,6 +77,15 @@ pub fn blank_line(input: &str) -> Res<&str, &str> {
     recognize(tuple((space0, alt((line_ending, eof)))))(input)
 }
 
+#[tracing::instrument(ret, level = "debug")]
+pub fn element_trailing_whitespace<'r, 's>(
+    context: Context<'r, 's>,
+    input: &'s str,
+) -> Res<&'s str, &'s str> {
+    start_of_line(context, input)?;
+    alt((eof, recognize(many0(blank_line))))(input)
+}
+
 #[tracing::instrument(ret, level = "debug")]
 pub fn trailing_whitespace(input: &str) -> Res<&str, &str> {
     alt((eof, recognize(tuple((line_ending, many0(blank_line))))))(input)