Add assets microservice base

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

backend/Dockerfile

@@ -0,0 +1,11 @@
+FROM rust AS builder
+WORKDIR /usr/src/qrust
+COPY . .
+ENV SQLX_OFFLINE true
+RUN cargo build --release
+
+FROM frolvlad/alpine-glibc AS assets
+WORKDIR /usr/src/assets
+COPY --from=builder /usr/src/qrust/target/release/assets .
+EXPOSE 7878
+CMD ["./assets"]