Schema Org Versions Save

• fix @id and identifier serialization for typed identifiers - #157

• add support for PHP 8

• add \Spatie\SchemaOrg\ReferencedType to reference types in schemas and graphs - #155

• fix empty string property values - #153

• add Multi-Typed-Entity support \Spatie\SchemaOrg\MultiTypedEntity - #148

• Upgrade to schema.org:v9 which includes all extensions

• Upgrade to schema.org:v8

Generated files with new JSON-LD source - some methods have been dropped which aren't part of the corresponding types but were listed in old RDFa - it's not a breaking release because of the same schema.org version and changes only because of schema file inconsistencies.

• fix \BadMethodCallException message thrown in \Spatie\SchemaOrg\Graph
• fix \Spatie\SchemaOrg\Graph docblock @method annotations

• add identifiers to \Spatie\SchemaOrg\Graph nodes #124