title: How to differentiate between a .ts file and a .d.ts
body: <p>Let's say I have the following folder structure:</p>
  <pre><code>-+ src/
  ---+ index.ts
  ---+ foobar.ts
  ---+ routes/
  -----+ router.d.ts
  -----+ router.ts
  </code></pre>
  <p>How would I be able to import only the <code>router.ts</code> file in <code>index.ts</code> and import <code>router.d.ts</code> in <code>foobar.ts</code>?</p>