Add example build to compile C code

Dockerfile

@@ -0,0 +1,13 @@
+FROM debian:bullseye as builder
+MAINTAINER restitux <restitux@ohea.xyz
+
+RUN apk add gcc
+RUN mkdir /src
+WORKDIR /src
+COPY main.c /src/
+RUN gcc main.c -o main
+
+FROM debian:bullseye
+
+COPY --from=builder /src/main /main
+ENTRYPOINT ["/main"]