Add base vocab anchor and link

Author: lornajane

versions/3.1.1.md

@@ -2705,7 +2705,7 @@ Where JSON Schema indicates that behavior is defined by the application (e.g. fo
 
 ##### Properties
 
-The OpenAPI Schema Object [dialect](https://tools.ietf.org/html/draft-bhutton-json-schema-00#section-4.3.3) is defined as requiring the [OAS base vocabulary](#oas-base-vocabulary), in addition to the vocabularies as specified in the JSON Schema draft 2020-12 [general purpose meta-schema](https://tools.ietf.org/html/draft-bhutton-json-schema-00#section-8).
+The OpenAPI Schema Object [dialect](https://tools.ietf.org/html/draft-bhutton-json-schema-00#section-4.3.3) is defined as requiring the [OAS base vocabulary](#base-vocabulary), in addition to the vocabularies as specified in the JSON Schema draft 2020-12 [general purpose meta-schema](https://tools.ietf.org/html/draft-bhutton-json-schema-00#section-8).
 
 The OpenAPI Schema Object dialect for this version of the specification is identified by the URI `https://spec.openapis.org/oas/3.1/dialect/base` (the <a name="dialect-schema-id"></a>"OAS dialect schema id").
 
@@ -2717,7 +2717,7 @@ The following properties are taken from the JSON Schema specification but their
 In addition to the JSON Schema properties comprising the OAS dialect, the Schema Object supports keywords from any other vocabularies, or entirely arbitrary properties.
 
 JSON Schema implementations MAY choose to treat keywords defined by the OpenAPI Specification's base vocabulary as [unknown keywords](https://datatracker.ietf.org/doc/html/draft-bhutton-json-schema-00#section-4.3.1), due to its inclusion in the OAS dialect with a [`$vocabulary`](https://datatracker.ietf.org/doc/html/draft-bhutton-json-schema-00#section-8.1.2) value of `false`.
-The OAS base vocabulary is comprised of the following keywords:
+<a name="base-vocabulary"></a>The OAS base vocabulary is comprised of the following keywords:
 
 ##### Fixed Fields