Export tsconfigs

We should export a number of standard configs that can be used in the `extends` option of a tsconfig:

```
"extends": "jsii/tsconfig.strict.json"
```

We should support:
- `jsii/tsconfig.strict.json`
- `jsii/tsconfig.generated.json`
- `jsii/tsconfig.minimal.json`

Example: https://www.npmjs.com/package/@tsconfig/node20

No files, tests, or entry points are named. Start by locating how this package currently publishes TypeScript configuration files, then verify that tsconfig.strict.json, tsconfig.generated.json, and tsconfig.minimal.json can each be resolved through the documented extends form; done means all three are included and usable from the package.

Written by the indexing model from the issue text.