Add coppercore to the docs

[jkleiber]

coppercore should be included in the docs website, probably in getting started

We should keep it brief, but answer the following:

What: what is coppercore?
Why: why did we make this library?
How: how do we use this in our robot code?

[aidnem]

There are currently some docs for coppercore in place. They need to be consolidated into a folder and also improved (add installation instructions). Ideally we'd have a homepage in the docs that we can link to if we start advertising CopperCore on CD.