Added a "tips" section

I thought it would be nice to highlight some tips so people can avoid stubbing their toes on things. For instance I didn't realize that propagit used two ports and I was trying to run a fleet hub for each of our environments. Scratching my head when things weren't working I started to dive into the code to realize that propagit needed two ports. 

Maybe the "tips" section will save some people a few cycles. :)