Add Dockerfile

Dockerfile

@@ -0,0 +1,13 @@
+# syntax=docker/dockerfile:1
+
+FROM golang:latest AS build
+WORKDIR /app
+COPY . .
+RUN go mod download
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o ./reddit_notify
+
+FROM alpine:latest
+WORKDIR /app
+COPY --from=build /app/reddit_notify /app/reddit_notify
+RUN chmod +x ./reddit_notify
+CMD [ "./reddit_notify" ]