docs: function findFirstListItem(lineNumber, cm) {
    let nextLineNumber = lineNumber;
    let lineText = cm.getLine(lineNumber);
  
    while (listRE.test(lineText)) {
      nextLineNumber -= 1;
      lineText = cm.getLine(nextLineNumber);
    }
  
    if (lineNumber === nextLineNumber) {
      nextLineNumber = -1;
    } else {
      nextLineNumber += 1;
    }
  
    return nextLineNumber;
  }