Release v0.3.0

Release OceanDataStore v0.3.0 including:

• Adding support for groups when writing or updating Zarr and Icechunk stores.

• Adding support for encoding when writing variables to Zarr and Icechunk stores.

• Improved support for CF-metadata attributes, including variables.

• Adding OceanDataCatalog to support groups in Zarr and Icechunk stores.

• Add Phase I Ocean Observations to JASMIN OS.

• Add processing scripts for Ocean Observations to data/ directory.

• Refactoring STAC creation to read global CF attributes & improve modularity for data producers.

• Improve documentation and README.md.

• Add GitHub templates for Issues.