title: tsc creates src folder in dist
body: <p>I have this folder structure:</p>
  
  <pre><code>- src
   - subdir1
   - subdir2
  </code></pre>
  
  <p>This is my <code>tsconfig.json</code>:</p>
  
  <pre><code>{
    "compilerOptions": {
      "target": "es2015",
      "module": "commonjs",
      "sourceMap": true,
      "declaration": true,
      "outDir": "./dist",
      "rootDir": "./src",
      "strict": true,
      "types": [
        "mocha",
        "node"
      ]
    }
  }
  </code></pre>
  
  <p>Calling <code>./node_modules/.bin/tsc</code> results in this folder structure:</p>
  
  <pre><code>- dist
    - src
     - subdir1
     - subdir2
  - src
   - subdir1
   - subdir2
  </code></pre>
  
  <p>Why is <code>src</code> included in <code>dist</code>?</p>