title: Adding Javascript to WKWebView
body: <p>Hi I know this seems like a super simple question, but I want to add this JS to my WebView: </p>
  
  <pre><code>&lt;script type='text/javascript' src='https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.2/MathJax.js?config=default&amp;#038;ver=1.3.8'&gt;&lt;/script&gt;
  </code></pre>
  
  <p>Now obviously I know this is HTML, but I am not sure what to put into 'evaluateJavaScript' in order to use the JS source. Sorry if this isn't very clear - I'm new to both Swift and JS. Thanks!</p>
  
  <p>My swift code: </p>
  
  <pre><code>func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
      self.webView.evaluateJavaScript("&lt;script type='text/javascript' src='https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.2/MathJax.js?config=default&amp;#038;ver=1.3.8'&gt;&lt;/script&gt;") { (nil, error) in
          print(error)
      }
  }
  </code></pre>