v3(docs): fix broken link

Author: Derik Evangelista

docs/v3/source/includes/resources/service_instances/_list_shared_spaces.md.erb

@@ -29,7 +29,7 @@ This endpoint lists the spaces that the service instance has been shared to.
 
 Name | Type | Description
 ---- | ---- | ------------
-**fields** (*experimental*)| [_fields parameter_](#fields-parameter) | [_Allowed values_](#shared-spaces-fields)
+**fields** (*experimental*)| [_fields parameter_](#fields-parameter) | [_Allowed values_](#shared-spaces-list-fields)
 
 ##### Shared Spaces List Fields