Is there a "home instance" browser extension?

When visiting a new lemmy instance to find communities, you have to copy the !community@server link from the description to your instance's search bar. If a chrome/firefox extension could detect that a lemmy instance is loaded and automatically add "Subscribe on [homeinstance.url]" buttons where the normal subscribe button would be, I think it'd go a long way toward making the "Fediverse" easy for new users. Apologies if this exists and I just couldn't find it.