Kayo Interesting idea. On a basic website, the jQuery would work. But, Flarum is a single page web app. And so, I've noticed adding JavaScript or jQuery to the head, won't always work. I had a similar idea to implement a very basic hashtagging feature. If someone types something like #apple, there's simple JavaScript out there that will turn that into a link, which could then search the forum for related posts. But, simply adding the JavaScript for this hashtagging feature to the head or footer doesn't work. It has to be added in a way so that it is re-loaded every time a post loads. Or in this case, every time the post editor appears. I don't know how to do that. I'm still, very slowly, learning how Flarum works. VERY slowly. I got lucky when I made my audio/soundmanager2 extension. Because, soundmanager2 has a built in "reload" function. Due to this, I was able to easily make it reload any time a post loads, which ensures the audio player shows up. But, again, with basic JavaScript/jQuery, I don't know how to make it work.
If anyone wants to give up the secret and let us know, please do! 🙂 How to make something, like a simple jQuery snippet, load each time the post editor loads, or each time a post loads?