title: Firebase rewrite based on subdomain
body: <p>I've got a project hosted on firebase. I'd like to use a domain and subdomain as follows:</p>
  
  <pre><code>example.com: rewrite to index-landing.html
  app.example.com: rewrite to index.html
  </code></pre>
  
  <p>Is that possible? I've tried the following under the hosting section of firebase.json:</p>
  
  <pre><code>"rewrites": [
    {
      "source": "https://example.com",
      "destination": "/index-landing.html"
    },
    {
      "source": "https://app.example.com/**",
      "destination": "/index.html"
    }
  ]
  </code></pre>
  
  <p>Any ideas?</p>