Consider including some base configs in the published `typescript` package

[weswigham]

Suggestion

With package-based paths now allowed within tsconfig extends clauses, we now have the opportunity to ship prescriptive base configs with our published package.

Use Cases

This could be useful for providing extra "defaults" for certain scenarios, like jsx, js, or a babel-y project, under paths like typescript/jsx, typescript/js and typescript/babel.

Examples

We publish, eg, react/tsconfig.json with contents:

{
    "compilerOptions": {
        "jsx": "react",
        "esModuleInterop": true,
        "allowSyntheticDefaultImports": true,
        "target": "es5",
        "module": "commonjs",
        "sourceMap": true
    }
}

so users can then write configs like:

{
    "extends": "typescript/react",
    "include": [ "src/**/*" ],
    "compilerOnSave": true
}

[RyanCavanaugh]

These are in the @tsconfig namespace instead