Removed the bit about running iron-router in dev from readme
Add installation instructions to README

The "mrt install iron-router-progress" (should be "add") on https://iron-router-progress.meteor.com/ tripped me up for a bit. It's wrong, but Meteorite not so helpfully responds with, "Done installing smart packages."
Merge pull request #16 from ryonlife/master

Add installation instructions to README