Add Environmental Variables to Unraid GUI Template

[frmattb]

I'm not sure where to post or who manages the Unraid Community Apps GUI as it all points here.

I manually add environmental variable to setup the email settings, port tunnelling, etc. Could we please add the environmental variables to the CA template?

https://github.com/TheSpaghettiDetective/obico-server/blob/release/docker-compose.yml#L13-L40