Fix ncorrect ports in documentation and add notes on how generate-config also generates certs bound to whatever hostname you give with --generate-config.

SYN-87 #resolved

Update README setup instructions to be correct. Make synapse spit out explanatory note when generating config to tell people to look at it and customise it.

Make the intro bit a separate section rather than have a 'quick start' section that only tells you how to get started half way through.