Unexpected Vector2 operator behaviour

Hi,

It seems like operators on Vector2 modify the base object instead of making a copy.

```cpp
raylib::Vector2 size{50,50};
raylib::Vector2 halfsize = size/2.0f;

std::cout << size.x << '\n';
std::cout << halfsize.x << '\n';
```

`
25
25
`

operator/ probably shoudn't modify the underlying object and be marked as const.

Merry christmas