added dockerfile

Dockerfile

@@ -0,0 +1,13 @@
+FROM golang:1.20-alpine
+WORKDIR /usr/src/app
+
+# pre-copy/cache go.mod for pre-downloading dependencies and only redownloading them in subsequent builds if they change
+COPY go.mod index-inlined-minified.html main.go ./
+RUN go mod download && go mod verify
+
+RUN go build -v -o /usr/local/bin/app ./...
+
+ENV PORT=8000
+ENV BIND=0.0.0.0
+
+CMD ["app"]