within method for Vec2 and Vec3

[whimbur-total]

A method to check if a point self is somewhere inside the area of a rectangle with point a being the top-left corner and point b being the bottom-right corner.

pub fn within(&self, a: &Vec2, b: &Vec2) -> bool

example:

let a = Vec2::ZERO;
let b = Vec2::ONE;

assert!(Vec2::(0.5, 0.5).within(&a, &b))
assert!(Vec2::ONE.within(&a, &b))
assert!(Vec2::(1.5, 0.25).within(&a, &b)) // Assertion fails because `1.5 > 1.0`