From the announcement:
I guess it’s time for another Run & Gun preview, so we’ve got one posted! This time we’ve posted the entire introductory section to give you an idea of what you’ll be able to find in the book and how it can be used. It’s totally free, and available at either the Battleshop or DriveThruRPG, so I can’t conceive of a single reason to not go out and get it. Enjoy!