Add Dockerfile

Dockerfile

@@ -0,0 +1,9 @@
+ARG CADDY_VERSION=2.10.0
+FROM caddy:${CADDY_VERSION}-builder AS builder
+
+RUN xcaddy build \
+    --with github.com/caddy-dns/hetzner 
+
+FROM caddy:${CADDY_VERSION}
+
+COPY --from=builder /usr/bin/caddy /usr/bin/caddy