feat: docker support (#43)

Dockerfile

@@ -0,0 +1,21 @@
+FROM cirrusci/flutter:3.3.7 AS flutter
+WORKDIR /app
+COPY ./ui/flutter/pubspec.yaml ./ui/flutter/pubspec.lock ./
+RUN flutter pub get
+COPY ./ui/flutter ./
+RUN flutter build web
+
+FROM golang:1.19.3 AS go
+WORKDIR /app
+COPY ./go.mod ./go.sum ./
+RUN go mod download
+COPY . .
+COPY --from=flutter /app/build/web/* ./cmd/web/dist
+RUN go build -tags nosqlite,web -ldflags="-s -w" -o dist/gopeed github.com/monkeyWie/gopeed/cmd/web
+
+FROM alpine:3.14.2
+LABEL maintainer="monkeyWie"
+WORKDIR /app
+COPY --from=go /app/dist/gopeed ./
+EXPOSE 9999
+ENTRYPOINT ["./gopeed"]