Document Unraid installation

[davidzwa]

"if this popup occurs, please change port 4000 in the settings to 4001 or another port that is unused. another option is to change the port on whatever is currently using it and keep fdmm on defaults"

"all these defaults will work fine - future updates to 1.7.x will be switching from a dedicated sqlite branch to a standardized monolithic container"

"click apply at bottom to install the container"

"once installed, please click the fdm monster icon and select WebUI or visit http://localhost:4000/ or http://your.server.ip.address.here:4000/"