`write_zarr_array` is not nested structure

[giovp]

HI,

after writing with write_zarr_array the content of the folder is the following

❯ lls new.zarrnew.zarr
.rw-r--r--@ 2.8M giovanni.palla 28 Apr 14:08 0.0.0

although I would have expected the following?

❯ tree
.
└── 0
    └── 0
        └── 0
            └── 0

yet the roundtrip as in the examples work, so not sure maybe expected behaviour?