Mute Autoplay Videos

I created this extension because I hate when websites autoplay videos and it blasts my headphones without warning. Especially news websites, Netflix, etc. This extension mutes all HTML5 videos upon opening a website. Obviously there are some websites where you want it to autoplay when opening (e.g. Youtube) so it's a simple two click process to add the current website as an exception. Seems to work well for my uses, let me know if you find any websites that it doesn't work on and I'll try to look into it.