Pdpinch/documentation updates

All the docs, including installation and course author documentation, are in the ReadMe now. 
I don't have strong feelings here.  I added it there because SGA is very similar to ORA2 in terms of scope and architecture, so I suggested adding it in the same place it was added.  I didn't put a lot of though into it, but I somewhat disagree with the sentiment that I don't want my platform to start if it doesn't exist.  I don't want a narrowly focus single page exception for the app being missing to bring down the whole platform.  The reality is that it just doesn't matter much though, so dealer's choice @pdpinch from my perspective.