fix long line diagnostic with long multiline string

src/parse.rs

@@ -133,11 +133,18 @@ pub fn parse(
  for line in tokens.split(|t| matches!(t.value, Newline)) {
  let mut heuristic = 0;
  let mut first = None;
- for tok in line {
+ let mut toks = line.iter().peekable();
+ while let Some(tok) = toks.next() {
  heuristic += match &tok.value {
  Spaces | Comment => 0,
  Simple(CloseBracket | CloseCurly | CloseParen) => 0,
  Simple(Underscore) => 0,
+ MultilineString(_) => {
+ while let Some(MultilineString(_)) = toks.peek().map(|t| &t.value) {
+ toks.next();
+ }
+ 1
+ }
  _ => {
  first = first.or(Some(&tok.span));
  1