improve documentation

[obbardc]

Currently documentation is a bit of a mess.

We need to remove the Github wiki & have one folder in the repo for a manual.

[danielhjames]

I agree, it needs an overhaul. I can take this on.

[obbardc]

Awesome, I am preparing the codebase for generating Pi images today & creating our own PDK channels.

I'll send you a buzz when I'm finished.

[obbardc]

I have remove the GitHub wiki, all documentation is back to being in the root of the project.

[obbardc]

I have added a note to README.me to let users know we are updating the documentation.