Add Port to UFW

I'm running UFW (uncomplicated firewall) to restrict traffic into my Linux system.

And while being super restrictive is generally a good thing, there are times when you have to poke a new hole and connect from another system inside the house.

Usually it's a new app running on a new port and since I never remember the command to allow this, here it is:

$ sudo ufw allow from 192.168.1.0/24 to any port 3100

You're welcome, future self!