docs(draft-06): add missing Core link to JSON Schema draft-wright-json-schema-01

Author: Bhumikagarggg

pages/draft-06/index.md

@@ -14,7 +14,7 @@ next:
 ---
 
 ### Draft-06 Documents
-
+- Core: [draft-wright-json-schema-01](https://json-schema.org/draft-06/draft-wright-json-schema-01.html) ([changes](https://json-schema.org/draft-06/draft-wright-json-schema-01.html#rfc.appendix.B))
 - Validation: [draft-wright-json-schema-validation-01](https://json-schema.org/draft-06/draft-wright-json-schema-validation-01.html) ([changes](https://json-schema.org/draft-06/draft-wright-json-schema-validation-01.html#rfc.appendix.B)) ([schema migration FAQ](https://json-schema.org/draft-06/json-schema-release-notes))
 - Hyper-Schema: [draft-wright-json-schema-hyperschema-01](https://json-schema.org/draft-06/draft-wright-json-schema-hyperschema-01.html) ([changes](https://json-schema.org/draft-06/draft-wright-json-schema-hyperschema-01.html#rfc.appendix.B)) ([hyper-schema migration FAQ](https://json-schema.org/draft-06/json-hyper-schema-release-notes))
 - [JSON Schema meta-schema](https://json-schema.org/draft-06/schema)