Add Dockerfile (#969)

Dockerfile

@@ -0,0 +1,23 @@
+# Improve build speed with cached deps
+ARG RUST_VERSION=1.70.0
+FROM lukemathwalker/cargo-chef:latest-rust-${RUST_VERSION} AS chef
+WORKDIR /app
+
+FROM chef AS planner
+COPY . .
+RUN cargo chef prepare --recipe-path recipe.json
+
+FROM chef AS builder
+COPY --from=planner /app/recipe.json recipe.json
+# Build dependencies - this is the caching Docker layer!
+RUN cargo chef cook --release --recipe-path recipe.json
+# Build application
+COPY . .
+RUN cargo build --release
+
+# why we dont use alpine for base image - https://andygrove.io/2020/05/why-musl-extremely-slow/
+FROM debian:bookworm-slim as runtime
+
+COPY --from=builder /app/target/release/rustic /usr/local/bin
+
+ENTRYPOINT ["/usr/local/bin/rustic"]