Make swap values case-INsensitive

I regularly run into the situation where I've used a swap (`hx-swap` and `hx-swap-oob`) value of `innerHtml` instead of `innerHTML` (for example), which causes things not to work as expected.

Why are `innerHTML` and `outerHTML` case-sensitive?

If there's a good reason, then these values should be clearly marked with a warning that they're case-sensitive, otherwise (my preference) they should be case-insensitive to avoid such problems in the first place.