feat: add Dockerfile for nginx/web builds

- add Dockerfile for web builds
- helps with ansible deployments

Signed-off-by: TheOneWithTheBraid <the-one@with-the-braid.cf>

Dockerfile

@@ -0,0 +1,10 @@
+FROM cirrusci/flutter as builder
+RUN sudo apt update && sudo apt install curl -y
+COPY . /app
+WORKDIR /app
+RUN ./scripts/prepare-web.sh
+RUN ./scripts/build-web.sh
+
+FROM docker.io/nginx:alpine
+RUN rm -rf /usr/share/nginx/html
+COPY --from=builder /app/build/web /usr/share/nginx/html