title: JS script in website won't run when it's a Firefox addon
body: <p>I'm making a basic start page to replace the &quot;blank&quot; option on Firefox, it's basically just an HTML website with some JS scripts added for some functionality. I added a script for a real time clock, which works fully when run as a website, but for some reason when I run it as an add-on, the scripts don't load (e.g. the clock doesn't appear) and I get this error in the console:</p>
  <pre><code>Content Security Policy: The page’s settings blocked the loading of a resource at inline (“script-src”).
  </code></pre>
  <p>I've taken a look at the <code>content_scripts</code> and <code>user_scripts</code> manifest keys, but I'm not quite sure where to start with those or if I'm even barking up the right tree with them.</p>
  <p>Thanks for your help in advance!</p>