title: ESLint issue: JSX not allowed in files in Typescript files
body: <p>I have .tsx files with jsx inside, but I'm getting this error in VSCode:</p>
  <p><code>JSX not allowed in files with extension '.tsx'eslintreact/jsx-filename-extension</code></p>
  <p>I added this to my package.json to fix it:</p>
  <p><strong>Package.json:</strong></p>
  <pre><code>&quot;eslintConfig&quot;: {
      &quot;rules&quot;: {
        &quot;react/jsx-filename-extension&quot;: [
          1,
          {
            &quot;extensions&quot;: [
              &quot;.tsx&quot;,
              &quot;.jsx&quot;
            ]
          }
        ]
      }
    }
  </code></pre>
  <p>Does anyone know what I'm doing wrong?</p>