update: add dockerfile

Dockerfile

@@ -0,0 +1,20 @@
+FROM golang:1.23.1-alpine3.20 AS go_builder
+
+WORKDIR /src
+COPY . .
+
+RUN apk update && apk upgrade && apk add --no-cache ca-certificates tzdata
+RUN update-ca-certificates
+RUN go build -o ./tmp/main
+
+FROM scratch
+
+WORKDIR /src
+
+COPY --from=go_builder /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=go_builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=go_builder /src/tmp/main /src
+
+ENV TZ Asia/Jakarta
+
+ENTRYPOINT ["./main"]