Adding docs for "overlay2.size" storage-opt
Adding docs for "overlay2.size" storage-opt

Signed-off-by: Dhawal Yogesh Bhanushali <4ddec4fd9d32628a52aa87e3ec1fd1b75dfec4f6@vmware.com>

redpanda/cli,riyazdf/cli,ashfall/cli,Zebrilee/cli,Zebrilee/cli,cpuguy83/cli,cpuguy83/cli,docker/cli,dnephin/cli,redpanda/cli,allencloud/cli,dnephin/cli,ashfall/cli,thaJeztah/cli,thaJeztah/cli,riyazdf/cli,allencloud/cli,docker/cli