This sounds like a very simple request, right? All I want to do is create a custom mapping of the keys on my keyboard to a set of Unicode characters ─ in fact, I just want to add a few special characters to the default English layout and that's it ─ and then be able to type using said mapping. I don't even necessarily need to download it on my computer; if I could just type using it online, akin to what this website offers.
However, I've searched all over the internet, and this just doesn't seem to be possible. I've found this website, but it appears to be pretty useless as it can only be integrated with physical keyboards. I have also found a bazillion font creators, but each of them requires me to draw each of the glyphs from scratch ─ something I have no interest in.
I have always found the Microsoft Keyboard Layout Creator, but unfortunately, I'm on a Chromebook.
Is there anything at all that I can do? Or will I have to resort to copying and pasting the special characters that I regularly use every single time?