Minor documentation issue

[systemdesignpartners]

Hi Jeremy,

Great little tool here for warming, thanks for it!

One possible add to the documentation, maybe in the same place where you make a NOTE of the invoke privs required. If running the warmer in a VPC, the fan-out process (applicable when concurrency > 1) requires the usual NAT Gateway access. If a NAT Gateway is already properly configured then most users will I think not notice that this is how fan-out works, until one of their teammates takes out their NAT Gateway without telling them :)

Thanks again for a great tool, Tony Sellitti

[jeremydaly]

Thanks, Tony. I'll add this in.