Probably not a great idea to make it so easy to scan the entire internet. Even providing the command in the readme before explaining why it is a bad idea.
Last I read about it, you can scan the entire IPv4 space for a port in about 40 minutes providing you have the bandwidth and a forgiving ISP. I see another comment claiming a tool can do it in 6 minutes. Easy at "apt get install" and a single command.
https://github.com/robertdavidgraham/masscan
Note that "scan the internet in 6 minutes" only means this tool is capable of generating packets fast enough on the host machine to theoretically do a 6 minute scan. In practice, the NIC, home network, and local ISP connection will bottleneck and the scan will be orders of magnitude slower.
Even then, you exist as an entity on the internet to have things connect to you. If there are ways in which you don't want to be connected to, you have a firewall to enforce that.