This can also be set up graphically using OpenWRT (which is a lighter-weight OS if you just want to do some networking and not use the Pi for anything else.

I should note that while the onboard WiFi is 802.11ac, I've never seen it get more than 60-70 Mbps in my own testing (in a variety of network environments), so if you want more speed, you might want to get an old n or ac router and flash it with OpenWRT instead.