Added step 1 goals to readme

I've filled in what I think should be some of our goals for step 1.
These are things I think are somewhat essential to the very basic
operation and core of the game. I could very well be wrong with some
of these, so let me know (or just change the readme).

To keep track of the goals and progress, there is a "---" next to
each goal. When finished, replace it with "-X-" to indicate completion