This is the page for the module with some examples, but chartjs has pretty extensive documentation and examples. You won't be able to find much about chartjs + Ignition but you should be able to apply the chartjs options etc to them.
I should also mention its a third-party module, so always make sure your customer and or employer is okay and comfortable with that. I may know how reputable Ben is, but they may not so please be mindful of that!