Add examples to Chapter 2: Introduction to Game Theory

[Jinglan]

Add more bimatrix game examples for each type of game

Add iterative game examples, with step by step explanations of iterated elimination

[yik8191]

I think the Mars-Earth game payoff would work with something like:

	Mars does not arm itself	Mars arms itself
Earth does not arm itself	(3, 3 )	(-3,5)
Earth arms itself	(5,-3)	(0,0)

so arming is dominant strategy, even it is in their best interests to cooperate. We could have a separate payoff matrix for the war declaration and put it under chicken/hawk-dove , say:

	Mars does not attack	Mars attacks
Earth does not attack	(0,0)	(-3,3)
Earth attacks	(3,-3)	(-10,-10)

and the optimal strategy depends on what the other player does. Unfortunately, in the name of
trying to get the best outcome for oneself, both end up risking the worst outcome (and we lead into mutually assured destruction from there?)