Mark init function as unsafe

[kitcatier]

Leafish/src/gl/mod.rs

Lines 25 to 29 in f44cf08

	pub fn init(context: glow::Context) {
	unsafe {
	CONTEXT = Box::into_raw(Box::new(context));
	}
	}

Hello, it is not a good choice to mark the entire function body as unsafe, which will make the caller ignore the safety requirements that the function parameters must guarantee, the developer who calls the init function may not notice this safety requirement.
Marking them unsafe also means that callers must make sure they know what they're doing.