title: Cannot GET / in simple React example
body: <p>I am doing some React book examples.<br>
  I get following error with below config after running <code>npm run start</code>:</p>
  <pre><code>Cannot GET /
  </code></pre>
  <p><b>package.json</b></p>
  <pre><code>{
    &quot;name&quot;: &quot;typescript&quot;,
    &quot;version&quot;: &quot;1.0.0&quot;,
    &quot;description&quot;: &quot;&quot;,
    &quot;main&quot;: &quot;zadanie1.js&quot;,
    &quot;scripts&quot;: {
      &quot;test&quot;: &quot;echo \&quot;Error: no test specified\&quot; &amp;&amp; exit 1&quot;,
      &quot;start&quot;: &quot;webpack-dev-server --mode development&quot;
    },
    &quot;keywords&quot;: [],
    &quot;author&quot;: &quot;&quot;,
    &quot;license&quot;: &quot;ISC&quot;,
    &quot;dependencies&quot;: {
      &quot;webpack&quot;: &quot;^5.74.0&quot;,
      &quot;webpack-cli&quot;: &quot;^4.10.0&quot;,
      &quot;webpack-dev-server&quot;: &quot;^4.11.0&quot;
    },
    &quot;devDependencies&quot;: {
      &quot;ts-loader&quot;: &quot;^9.3.1&quot;,
      &quot;typescript&quot;: &quot;^4.8.3&quot;
    }
  }
  </code></pre>
  <p><b>tsconfig.json</b></p>
  <pre><code>{
    &quot;compilerOptions&quot;: {
      &quot;target&quot;: &quot;ES5&quot;,
      &quot;module&quot;: &quot;CommonJS&quot;,
      &quot;sourceMap&quot;: true,
      &quot;removeComments&quot;: true
    },
  }
  </code></pre>
  <p><b>webpack.config.js</b></p>
  <pre><code>const path = require('path');
  module.exports = {
      entry: {
      main: path.join(__dirname, 'zadanie1.ts'),
      },
      output: {
          filename: &quot;zadanie1.js&quot;,
          path: __dirname,
      },
      module: {
          rules: [
              {
                  test: /\.tsx?$/,
                  loader: &quot;ts-loader&quot;,
                  exclude: /node_modules/,
              },
          ]
      },
      resolve: {
          extensions: [&quot;.tsx&quot;, &quot;.ts&quot;, &quot;.js&quot;]
      },
  };
  </code></pre>
  <p><b>index.html</b></p>
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang=&quot;en&quot;&gt;
  &lt;head&gt;
      &lt;meta charset=&quot;UTF-8&quot;&gt;
      &lt;title&gt;Title&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;script src=&quot;zadanie1.js&quot; type=&quot;text/javascript&quot;&gt;&lt;/script&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  <p><b>zadanie1.ts</b></p>
  <pre><code>document.write(&quot;Hello World!&quot;);
  </code></pre>
  <p>I have added <code>publicPath: &quot;/&quot;</code> to <b>webpack.config.js</b> but nothing changed.
  <br>
  This example seems pretty easy but somehow this does not work.
  Book is from 2021 (it might be outdated in some places as React is changing alot)</p>