Found an off-the-shelf box that I used as a web site server to the AREDN network.
At the risk of sounding like a paid advertisement (I'm only a happy user, no other connection or being paid). 
If you want the convenience and memory space a USB stick would provide you in building a web site for the AREDN mesh net, you could get a GL-AR150 router from GL innovations. It's a small box with a LAN port, a WAN port, and a USB port. Runs off 5VDC or power over ethernet.
This router can be used to provide web pages, stored on a USB stick, as an "advertised service" of your AREDN node.
First you configure the router
The AR150's WAN port will connect to the AREDN node's LAN port (via a smart switch if need be). Make the AR150's WAN port be a DHCP client, and the AREDN node will give it an IP address. As for the AR150's LAN port, give it a static IP address in the range of your home network (like 192.168.1.181). There seems to be no issue having this LAN port connected to a home network, and its WAN port connected to an AREDN node, which also has its WAN port connected to the same home network. No tail chasing happens. Configure the AR150's "WAN access port" to something like 8008, like I did here. This port number is also used under the "advertised services" config in the AREDN node. And be sure to check the "Enable WAN access" as well. Leave the password blank. And don't require the S/N. Click "apply".
You need to use the router's LAN port to access its OpenWRT. To get at it, click "Advanced settings" in the upper right of the screen, as seen in the top image of this web page. In the OpenWRT "Startup" tab (under "System") scroll down to "Local Startup" and add the line
ln -s /mnt/sda1 /www
just above "exit 0".
This makes the contents of the USB stick show up in a subdirectory in the router's /www directory. You then can create a link to it under "advertised services" in the AREDN node's "Port Forwarding, DHCP, and Services" tab. Leave off the /www/ part of the path, as that is assumed by the node.
The underlined in the above shows the node's assignment of the GL-AR150 router, and the advertised service information.
First step is to give your AR150 OpenWRT router a hostname under 'DHCP Address Reservations'. Hopefully, you'll find your AR150 OpenWRT router under 'Current DHCP Leases', in which case you can copy the MAC address, and select its IP address to fill in the blanks. And you have to make up a hostname, best to use something that will be unique to the entire mesh network, something with your callsign in it. Click 'add' and then 'save changes'.
Now the advertised service config: the 'name' is what will show up on other mesh nodes as the name of your service. Check 'link'. Put 'http' in the next blank. The 'URL' should have as a selection your new hostname. In the next blank put '8008' (or whatever port number you used setting up the AR150 above). And in the last blank you put the path "sda1/"(leave out the /www/ part) and filename of the html file that is your web page. Click 'add' and then 'save changes'.
You may have to do a reboot of the node. After that, go to 'mesh status' and you should see, at the top, under 'Local hosts', your advertised service. You should be able to go to it when you click this link. And other hams on the mesh network you're a part of should see and be able to click it as well.
The company's site is www.gl-inet.com