Add WireWorld example

[jeffkreeftmeijer]

Thanks for your work on bevy_life! This patch adds a WireWorld example based on the existing game of life one, which I worked while learning to use the library. It shows using WireWorld2dPlugin and WireWorldCellState, as well as an example of using a time step to slow the simulation down.

[ManevilleF]

Thanks for this PR ! I'll review it in a bit.

There already is a well featured wireworld implementation using bevy life but a simpler example in this repo makes sense