title: how to eliminate the render blocking in angular-cli site?
body: <p>after running <code>ng build --prod</code> I can go into my <code>index.html</code> file in the newly created dist folder and add the <code>async</code> attribute to the bundled script tags to keep them from being blocking. this helps with website speed but sporadically crashes the site. is there an option in the <code>angular-cli.json</code> that would add this for me during the build in a better way?
  i ran my site through google's test my website and the only thing i have left to fix is Eliminate render-blocking JavaScript and <a href="/questions/tagged/css" class="post-tag" title="show questions tagged &#39;css&#39;" rel="tag">css</a> in above-the-fold content</p>
  
  <p>below is a the more specific result i get from <a href="https://developers.google.com/speed/pagespeed/insights/" rel="noreferrer">https://developers.google.com/speed/pagespeed/insights/</a></p>
  
  <p>Eliminate render-blocking JavaScript and CSS in above-the-fold content</p>
  
  <p>Your page has 4 blocking script resources and 1 blocking CSS resources. This causes a delay in rendering your page. None of the above-the-fold content on your page could be rendered without waiting for the following resources to load. Try to defer or asynchronously load blocking resources, or inline the critical portions of those resources directly in the <a href="/questions/tagged/html" class="post-tag" title="show questions tagged &#39;html&#39;" rel="tag">html</a>. Remove render-blocking JavaScript:</p>