include an example cmd

cmd/Dockerfile

@@ -0,0 +1,16 @@
+FROM golang:alpine AS builder
+RUN apk --no-cache --no-progress add upx
+WORKDIR /go/build
+
+COPY . .
+RUN echo Building && \
+    go get -u && \
+    env CGO_ENABLED=0 go build -trimpath -ldflags="all=-s -w -buildid= -X main.version=v$(cat VERSION) -X main.buildtime=$(date +%FT%T%z)" -o pathway && \
+    echo Compressing && \
+    upx pathway > /dev/null
+
+FROM scratch
+COPY --from=builder /go/build/pathway /pathway
+
+EXPOSE 8080
+CMD ["/pathway"]