Add missing multicluster CLI Dockerfile (#235)

Author: mircea-cosbuc

tools/multicluster/Dockerfile

@@ -0,0 +1,10 @@
+FROM golang:1.19 as builder
+WORKDIR /go/src
+ADD . .
+
+RUN CGO_ENABLED=0 go build -a -buildvcs=false -o /go/bin/mongodb-multicluster
+
+FROM scratch
+COPY --from=builder /go/bin/mongodb-multicluster /go/bin/mongodb-multicluster
+
+ENTRYPOINT [ "/go/bin/mongodb-multicluster" ]