Add schema metadata
Added `id`, `$schema`, `description`
MODIFY
schemas/v3.0/schema.yaml
schemas/v3.0/schema.yaml
+id: https://spec.openapis.org/oas/3.0/schema/2019-04-02
+$schema: http://json-schema.org/draft-04/schema#
+description: Validation schema for OpenAPI Specification 3.0.X.
type: object
required:
- openapi

Add schema metadata

Added `id`, `$schema`, `description`