add dockerfile to build into container

Dockerfile

@@ -0,0 +1,23 @@
+# syntax=docker/dockerfile:1
+FROM golang:1.21 AS build-stage
+WORKDIR /app
+
+COPY go.mod ./
+RUN go mod download
+
+COPY *.go ./
+COPY ./templates/ ./templates/
+
+RUN CGO_ENABLED=0 GOOS=linux go build -o /evilthings
+
+FROM gcr.io/distroless/base-debian11 AS build-release-stage
+
+WORKDIR /
+
+COPY --from=build-stage /evilthings /evilthings
+
+EXPOSE 8080
+
+USER nonroot:nonroot
+
+ENTRYPOINT [ "/evilthings" ]