Add a custom loading screen

[r4pt0s]

Kaplayjs has a default loading screen which just a loading bar.
To make waiting for loading assets more fun, we need a custom loading screen.
If possible with a custom loading bar.

Everything should be compatible with our ZTM styles and also the game.
For this we need the code and also the design.

[parthib2004]

Please assign these to me.

[r4pt0s]

@parthib2004 done.
Go for it 🚀🏃🏽‍♂️‍➡️