[Feature] Add types field to manifest for TypeScript support

[grapgrap]

• I'd be willing to implement this feature (contributing guide)
• This feature is important to have in this repository; a contrib plugin wouldn't do

Disclaimer: This content was written with the help of AI translation.

ref: #4834

Describe the user story

I want to make some util using @yarnpkg/parser.

But it did not have types field on manifest, I can't develop on typescript codebase.

Describe the solution you'd like

According to this typescript docs, Package describe types field for type file.

// package.json
{
    "name": "my-package",
    "type": "module",
    "exports": {
        ".": {
            // Entry-point for `import "my-package"` in ESM
            "import": {
                // Where TypeScript will look.
                "types": "./types/esm/index.d.ts",
                // Where Node.js will look.
                "default": "./esm/index.js"
            },
            // Entry-point for `require("my-package") in CJS
            "require": {
                // Where TypeScript will look.
                "types": "./types/commonjs/index.d.cts",
                // Where Node.js will look.
                "default": "./commonjs/index.cjs"
            },
        }
    },
    // Fall-back for older versions of TypeScript
    "types": "./types/index.d.ts",
    // CJS fall-back for older versions of Node.js
    "main": "./commonjs/index.cjs"
}

Describe the drawbacks of your solution

The implementation is straightforward and follows TypeScript's official recommendations. There are no significant drawbacks as this change only adds type definitions without modifying existing functionality

Describe alternatives you've considered