Create basic CHEBI slim

[matentzn]

We propose the design of a CHEBI slim for use across OBO ontologies. The technique is the same as what we use for NCBITaxon and PRO Slims: We curate a seed file and extract a modules with that seed.

Arguments:

• Chebi is enormously huge, which precludes the complete automation of release pipelines using GitHub actions.
• Chebi's deposition system is sometimes a bit flaky which causes dozen of OBO release processes to break for OBO ontologies
• Chebi QC is a bit weak, which occasionally results in broken release files, which in turn cause broken release pipelines, see also Chebi issue above.

Related issues

• Aim 1.3 Extend and improve the semantic infrastructure required for phenotype ontology development monarch-initiative/phenomics_first_resource#3