Cannot Find TypeScript Definitions

Hello!

Apologize for being a dingus on this.

I've tried
```bash
yarn add --registry=https://registry.npmjs.org @types/util
```

But this is what I get
```
dev ±✚  ⬡ v12.17.0  yarn add --registry=https://registry.npmjs.org @types/util
yarn add v1.22.5
[1/4] 🔍 Resolving packages...
error An unexpected error occurred: "https://registry.npmjs.org/@types%2futil: Not found".
info If you think this is a bug, please open a bug report with the information provided in "/Users/lknecht/Repositories/palantir-test-data-helpers/yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/add for documentation about this command.
```

Can you provide guidance on how to add type definitions for this library?