Invalid plugins? filebrowser integration

Inside builder folder

`docker build . -t caddybuilder; docker run --rm -v $(pwd):/install -v /root/src/cabby-docker/builder/go/:/go/ -e PLUGINS=git,filemanager,cors,realip,expires,cache caddybuilder`

from

https://github.com/abiosoft/caddy-docker/tree/master/builder

when i check

`/root/src/cabby-docker/builder/go/src/github.com/mholt/caddy/caddyhttp/filemanager.go`

its contents dont point to anything

`package caddyhttp`

`import _ "github.com/hacdias/filemanager/caddy/filemanager"`

I am trying to integrate this docker image with

https://github.com/filebrowser/filebrowser

how should i do this? should i replace .go files with these on /caddyhttp/?

https://github.com/filebrowser/filebrowser/tree/master/caddy