nomenclature

What's Changed Second PR to update the Nomenclature documentation by @GretchenSchowalter in https://github.com/IAMconsortium/nomenclature/pull/242 MetaCode and MetaCodeList classes with allowed_values attribute by @GretchenSchowalter in https://github.com/IAMconsortium/nomenclature/pull/246 Streamline code list filter by @phackstock in https://github.com/IAMconsortium/nomenclature/pull/245 Update required data validator by @phackstock in https://github.com/IAMconsortium/nomenclature/pull/243 Exclude defaults for yaml export by @phackstock in https://github.com/IAMconsortium/nomenclature/pull/247 Added the countries attribute and check_iso3_codes() method to RegionCode object by @GretchenSchowalter in https://github.com/IAMconsortium/nomenclature/pull/240 General cleanup by @phackstock in https://github.com/IAMconsortium/nomenclature/pull/244 Full Changelog: https://github.com/IAMconsortium/nomenclature/compare/v0.9...v0.9.1If you use this package please cite the doi corresponding to the release use