To fix before next release

[leifdenby]

• update usage instructions in README to include that the validator can now be run directly for releases on pypi.org (since we have these)
• add warning in checks that rely on storage_options if these are not present. This will happen by default when not using the cli, because we in the cli interface inject these as an attribute on the dataset since the consolidated meta-data check require these. Currently I also insert the storage_options in ci on https://github.com/mlcast-community/mlcast-datasets, but we should add a warning in case people want to use the python api

[leifdenby]

Closed with:

• updating README for pypi+uvx README instructions: Docs/pypi install info in readme #32
• better handling of zarr consolidate metadata check (including warnings for missing storage_options in case where dataset can't be read): Fail zarr format specification requirements if format cannot be inferred #31