Added docker file to generate the image.

Dockerfile

@@ -0,0 +1,24 @@
+# syntax=docker/dockerfile:1
+FROM alpine:latest as base
+
+# Build Stage:
+FROM base AS build
+RUN apk add git build-base
+RUN git clone https://undercroft.ocathain.ie/barra/the-worlds-least-useful-clock.git
+RUN gcc the-worlds-least-useful-clock/the-worlds-least-useful-clock.c
+
+# Final Stage:
+FROM base AS final
+COPY --from=build a.out /bin/useless-clock
+ARG UID=10001
+RUN adduser \
+    --disabled-password \
+    --gecos "" \
+    --home "/nonexistent" \
+    --shell "/sbin/nologin" \
+    --no-create-home \
+    --uid "${UID}" \
+    appuser
+USER appuser
+COPY --from=build a.out /bin/useless-clock
+ENTRYPOINT [ "/bin/useless-clock" ]