added docker as an example

Dockerfile

@@ -0,0 +1,28 @@
+# Nix builder
+FROM nixos/nix:latest AS builder
+
+# Copy our source and setup our working dir.
+COPY . /tmp/build
+WORKDIR /tmp/build
+
+# Build our Nix environment
+RUN nix \
+    --extra-experimental-features "nix-command flakes" \
+    --option filter-syscalls false \
+    build
+
+# Copy the Nix store closure into a directory. The Nix store closure is the
+# entire set of Nix store values that we need for our build.
+RUN mkdir /tmp/nix-store-closure
+RUN cp -r $(nix-store -qR result/) /tmp/nix-store-closure
+
+# Final image is based on scratch. We copy a bunch of Nix dependencies
+# but they're fully self-contained so we don't need Nix anymore.
+FROM scratch
+
+WORKDIR /app
+
+# Copy /nix/store
+COPY --from=builder /tmp/nix-store-closure /nix/store
+COPY --from=builder /tmp/build/result /app
+CMD ["/app/bin/testdata"]