set Dockerfile multi-stage

Author: Nebell

Dockerfile

@@ -7,4 +7,4 @@ RUN cd src && CGO_ENABLED=0 GOOS=linux go build -o ding-dong-bot -v ./examples/d
 FROM alpine AS prod
 WORKDIR /root/
 COPY --from=builder /root/src/ding-dong-bot .
-ENTRYPOINT ["./ding-dong-bot"]
+ENTRYPOINT ["./ding-dong-bot"]