GlfwInit should be inside an if statement

[frederikja163]

glfwInit should be placed inside an if statement like so

if (!glfwInit()){
    // Handle glfw error.
}

To handle the glfw error it might be best to throw an exception. Might aswell teach glfw best practices from day 1 :) https://www.glfw.org/docs/3.3/quick.html