title: "'rootDir' is expected to contain all source files" in monorepo
body: <p>I'm working on converting a large(ish) monorepo into TypeScript for a client, however, I'm pretty new to TS myself and have run into an error that I can't find an obvious fix for.</p>
  
  <p><code>TS6059: File '[path to repo root]/packages/config/globals.ts' is not under 'rootDir' '[path to repo root]/packages/components/src'. 'rootDir' is expected to contain all source files.</code></p>
  
  <p>The <code>globals.ts</code> file isn't supposed to live in the <code>components</code> package, it belongs to the <code>config</code> package so I don't really understand the error.</p>
  
  <p>I have a main tsconfig file in the root of the repo (<a href="https://github.com/serge-web/serge/blob/feature/333-game-admin-channel/tsconfig.json" rel="noreferrer">https://github.com/serge-web/serge/blob/feature/333-game-admin-channel/tsconfig.json</a>) and then each package has it's own tsconfig file which extends that one. The one for the <code>components</code> package is here: <a href="https://github.com/serge-web/serge/blob/feature/333-game-admin-channel/packages/components/tsconfig.json" rel="noreferrer">https://github.com/serge-web/serge/blob/feature/333-game-admin-channel/packages/components/tsconfig.json</a></p>
  
  <p>I assume I am extending the tsconfig files in the packages incorrectly or I have used <code>references</code> incorrectly but I can't find the correct way to do this.</p>
  
  <p>Here is a link to the repo if you need to see the structure: <a href="https://github.com/serge-web/serge/tree/feature/333-game-admin-channel" rel="noreferrer">https://github.com/serge-web/serge/tree/feature/333-game-admin-channel</a></p>