Dockerfile comment added

Author: rcmadhankumar

Dockerfile

@@ -17,12 +17,13 @@ WORKDIR /go/src/sigs.k8s.io/ibm-powervs-block-csi-driver
 ADD . .
 RUN make driver
 
+# debian base image
 FROM k8s.gcr.io/build-image/debian-base:v2.1.3 AS debian-base
 RUN clean-install ca-certificates e2fsprogs mount udev util-linux xfsprogs bash multipath-tools sg3-utils
 COPY --from=builder /go/src/sigs.k8s.io/ibm-powervs-block-csi-driver/bin/ibm-powervs-block-csi-driver /ibm-powervs-block-csi-driver
 ENTRYPOINT ["/ibm-powervs-block-csi-driver"]
 
-
+# centos base image
 FROM quay.io/centos/centos:stream8 AS centos-base
 RUN yum install -y util-linux nfs-utils e2fsprogs xfsprogs ca-certificates && yum clean all && rm -rf /var/cache/yum
 COPY --from=builder /go/src/sigs.k8s.io/ibm-powervs-block-csi-driver/bin/ibm-powervs-block-csi-driver /ibm-powervs-block-csi-driver