title: Parcel does not reload changes to HTML page
body: <p>I'm trying to get up and running with <a href="https://parceljs.org" rel="nofollow noreferrer">Parcel</a> but I can't get a basic setup to work. I would like to serve a static HTML page that automatically reloads when it's changed.</p>
  
  <p>When I go to <code>http://localhost:1234</code>, Parcel serves my page. If I change anything in the <code>index.html</code>, it does not reload... or it reloads with an empty response.</p>
  
  <p><strong>versions</strong></p>
  
  <pre><code>parcel: 1.12.4
  npm: 6.12.1
  node: v13.3.0
  </code></pre>
  
  <p><strong>index.html</strong></p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;!doctype html&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;title&gt;Tinsel town&lt;/title&gt;
  
          &lt;script src="app.js"&gt;&lt;/script&gt;
      &lt;/head&gt;
  
      &lt;body&gt;
          &lt;h1&gt;Tinsel…&lt;/h1&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p><strong>app.js</strong></p>
  
  <pre class="lang-js prettyprint-override"><code>// empty
  </code></pre>
  
  <p><strong>Shell</strong></p>
  
  <pre><code>matt$ parcel index.html --log-level 5
  [13:20:42]: Server running at http://localhost:1234 
  [13:20:42]: Building...
  [13:20:42]: Building index.html...
  [13:20:43]: Building app.js...
  [13:20:43]: Built app.js...
  [13:20:43]: Built index.html...
  [13:20:43]: Producing bundles...
  [13:20:43]: Packaging...
  [13:20:43]: Building hmr-runtime.js...
  [13:20:43]: Built ../../../usr/lib/node_modules/parcel-bundler/src/builtins/hmr-runtime.js...
  [13:20:43]: ✨  Built in 477ms.
  [13:20:49]: Building...
  [13:20:49]: Producing bundles...
  [13:20:49]: Packaging...
  [13:20:49]: ✨  Built in 2ms.
  </code></pre>