Apple Magic keyboard protection

Not a case, but a protection for the keys, when you put the keyboard in a bag.

There are variants:
- EU -> for european layouts
- US -> for american layouts
- universal -> works with EU + US

As most printers will not be able to print the entire piece, I split it into left and right parts.
If you're lucky and have one which can, simply print the "-both" part.
Otherwise, print "-L" and "-R" parts, then eventually glue them together.

Also, I've made an optional reinforcement part, with Apple logo.
After glued both parts, it seems strong enough but the seam is still visible, so I'm using it to hide it.
(Perhaps it could have been camouflaged instead with post-treatment, paint or sticker...)

Another optional parts "decoration-1" and "decoration-2" can be printed and glued later.
(No purpose other than aesthetic.)

Easy to print, no supports required. Can be used with my [Magic keyboard riser](https://www.thingiverse.com/thing:7148373).