Mint new terms in ENVO for different layers of `soil_horizon`

[sujaypatil96]

There's a term in the MIxS standard/specification called soil_horizon: https://genomicsstandardsconsortium.github.io/mixs/0001082/ which has a few permissible values that it can take as its value: https://genomicsstandardsconsortium.github.io/mixs/SoilHorizonEnum/#permissible-values

I looked through the OLS system, and the only two permissible values that I could find mappings for in the ENVO ontology were –

• O horizon: http://purl.obolibrary.org/obo/ENVO_03600018
• M horizon (not present in MIxS yet): http://purl.obolibrary.org/obo/ENVO_03600011

Ideally, we would have controlled vocabulary for all the terms in the enumeration for soil_horizon described/defined in ENVO. We need to mint new terms in the ontology for that.