Update and rename Dockerfile to Containerfile

Containerfile

@@ -0,0 +1,11 @@
+FROM --platform=${BUILDPLATFORM} golang:1.18-bullseye AS build
+WORKDIR .
+ENV CGO_ENABLED=0
+ARG TARGETOS
+ARG TARGETARCH
+RUN GOOS=${TARGETOS} GOARCH=${TARGETARCH} go build -o /bin/rawleydotxyz .
+
+FROM scratch AS bin
+COPY --from=build /bin/rawleydotxyz /
+EXPOSE 8080/tcp
+CMD ["/rawleydotxyz"]