add docker container

Dockerfile

@@ -0,0 +1,15 @@
+# Build stage
+FROM golang:1.25-alpine AS builder
+
+WORKDIR /app
+COPY . .
+RUN go build -o server ./cmd/server
+
+# Runtime stage
+FROM alpine:3.20
+
+WORKDIR /app
+COPY --from=builder /app/server /usr/local/bin/server
+EXPOSE 8080
+
+ENTRYPOINT ["/usr/local/bin/server"]