Q: How do I Turn an iMac G4 Into a Web Server?

I've got an old iMac G4 (700Mhz, running 10.4 Tiger) that I'd like to turn into a web server. But it's connected to an AirPort network, and there's no place I can connect it to Ethernet (except on the Ethernet ports on our AirPort Time Capsule). So my website is only available on our WiFi network.  I've been trying to make it so anyone can get to that website, but everything I can't figure it out. I'm using the most recent AirPort Time Capsule connected to a cable modem provided by Charter.

(By the way, I don't care about the URL of the website- my IP address is fine for what I'm going to be using this for)