message: fix void type
diff: @@ -208,6 +208,8 @@ function propsTable(
  function propType(value: any, exports: any[], dir: string): any {
  switch (value.kind) {
  + case 'VoidType':
  + return '<code>void</code>';
  case 'StringType':
  return '<code>string</code>';
  case 'BooleanType':
  