Move config files and folders

.goreleaser.yml

Makefile

client/client.go

client/ntfy-client.service

cmd/serve.go

cmd/subscribe.go

docs/config.md

docs/faq.md

docs/install.md

scripts/postinst.sh

scripts/postrm.sh

scripts/preinst.sh

server/config.go

server/config_test.go

server/ntfy.service

server/server.go

server/server.yml

server/visitor.go