message: Handle mustEscape for interpolated-code token
diff: @@ -440,7 +440,8 @@ export const plugin: Plugin = {
  result += '| ';
  break;
  }
  - result += `#{${token.val}}`;
  + result += token.mustEscape ? '#' : '!';
  + result += `{${token.val}}`;
  break;
  case 'code':
  result = printIndent(previousToken, result, indent, indentLevel);
  