title: How to make href anchors in iframe `srcdoc` actually work
body: <p>I have some html content that I am loading in an iframe. I'm loading the html content through the <code>srcdoc</code> attribute. Unfortunately, when following  anchor tag links inside the iframe it loads the entire page within the iframe, instead of scrolling to the tag with the linked id.</p>
  
  <p>JSFiddle that demonstrates the problem: <a href="https://jsfiddle.net/kzLdqjgs/5/" rel="noreferrer">https://jsfiddle.net/kzLdqjgs/5/</a></p>
  
  <p>I can get the anchor tags to work using <code>src="data:text/html,&lt;p&gt;my html&lt;/p&gt;"</code> but I'm curious as to why it doesn't with with srcdoc. Furthermore, the src attribute for some implementations apparently has a limit of 32,768 characters and the content I'm trying to load is over 60k characters in length (though this seems to work fine in Chrome).</p>