forked from rook/rook
https://github.com/rook/rook/pull/11845 added dynamic label `mgr_role`. The example yaml files are updated but this doc is missed. I think it would be better to refer to `deploy/examples` but I find all other places are not doing that. So keep it inlined to be consistent. Signed-off-by: Bin Wang <bin.wang@mail.binwang.me>