pixel.RGB555 or pixel.BGR555 ?

[sago35]

@aykevl
It might be better to name pixel.RGB555 as pixel.BGR555.
I think the name becomes very important when using pixel.NewImageFromBytes().

https://github.com/tinygo-org/drivers/blob/v0.33.0/pixel/pixel.go#L147-L151

I’m planning to add either ARGB1555 or ABGR1555 in the near future.
When adding this, whether it’s RGB or BGR will become very important.

(I’m planning to add support for loading transparent PNGs.)