Nginx configuration fixes for large libraries

[postpersonality]

It seems Tinfoil app parses only a small part of index (GET /) and if library is fairly large (and directories listing comes before the files listing) then it cannot find /shop.tfl and does not recognize shop at Tinfoil app start.

Additionally it has correct supervisor script. See docker documentation https://docs.docker.com/config/containers/multi-service_container/

And small chore in part of optimization of docker build speed (order of commands + cleaned up docker context).

Docker image for checking out the fixes: https://hub.docker.com/r/postpersonality/ownfoil