#### Improve long mapped type to across multiple line (#18779 by @kovsu)

<!-- prettier-ignore -->
```flow
// Input
type MappedType = {
  [KeyType in ValueType extends string ? VeryLongStringTypeNameHere : VeryLongNumberTypeNameHere]: KeyType
}

// Prettier stable
type MappedType = {
  [KeyType in ValueType extends string
      ? VeryLongStringTypeNameHere
      : VeryLongNumberTypeNameHere]: KeyType,
};

// Prettier main
type MappedType = {
  [
    KeyType in ValueType extends string
      ? VeryLongStringTypeNameHere
      : VeryLongNumberTypeNameHere
  ]: KeyType,
};
```
