Review/update https://typescriptlang.org/tsconfig for TS 6.0

@RyanCavanaugh がすでに取り組んでいます。

2026年4月14日 から。

### Acknowledgement

- [x] I acknowledge that issues using this template may be closed without further explanation at the maintainer's discretion.

### Comment

There is a lot of information on https://typescriptlang.org/tsconfig that's just plain wrong now that 6.0 has been released.

Some things I've noticed so far:

1. [The documentation for the default value of `target`](https://www.typescriptlang.org/tsconfig/#target) is currently wrong (at least the "…`ES5` otherwise" bit). This section also still mentions `ES3` as an allowed `target` value.

1. [The documentation for `types`](https://www.typescriptlang.org/tsconfig/#types) still says:

> By default all _visible_ ”`@types`” packages are included in your compilation. Packages in `node_modules/@types` of any enclosing folder are considered _visible_.

But `types` actually now defaults to `[]`, and `@types` packages need to be explicitly listed to be included in the global scope.

1. [The `paths` documentation](https://www.typescriptlang.org/tsconfig/#paths) says:

> A series of entries which re-map imports to lookup locations relative to the [`baseUrl`](https://www.typescriptlang.org/tsconfig/#baseUrl) if set, or to the tsconfig file itself otherwise.

But I'm pretty sure the first part of that is a lie.

1. [`rootDir`](https://www.typescriptlang.org/tsconfig/#rootDir) talks about its default being computed from "the longest common path of all non-declaration input files" (both in the description and the "Default" section on the right side), but really it's just the parent directory of the tsconfig file.

1. [`module`](https://www.typescriptlang.org/tsconfig/#module) still refers to `amd` & `umd`, but those no longer exist.

There are likely additional things that are outdated; the above was just based on a quick skim.