I did something like this a couple of months ago. I wrote a simple firefox extension which adds a button near the url bar which calls youtube-dl to download the current URL on a predefined folder. It needs an intermediate "helper" which is registered via the Windows registry (just make a key for it). All the helper does though is just call youtube-dl.

It sounds complicated but i had never written any firefox addon at all before trying it and it took me less than an hour to write the entire thing just by following the docs. The biggest change was switching from regular firefox to developer edition so i can disable signature checking for addons (the regular firefox doesn't allow that), but so far all that meant is that the red icon globe is now blue and i get more frequent updates.

None of that is available publicly though since it is very configuration-specific - and really all it does is to call 'youtube-dl' - but it is easy to replicate. Also learning to make some "personal" addons might be helpful in the future, similar to how you customize Emacs or Vim.