fixing reference and adding changelog

Signed-off-by: Tokesh <[email protected]>

CHANGELOG.md

@@ -21,6 +21,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Added `s` to `/_ingest/processor/grok` ([#689](https://github.com/opensearch-project/opensearch-api-specification/pull/689))
 - Added schema for security API error responses ([#646](https://github.com/opensearch-project/opensearch-api-specification/pull/646))
 - Added `aggregations` to `/nodes/_usage/{metric}` requests and responses ([#615](https://github.com/opensearch-project/opensearch-api-specification/pull/615))
+- Added `_type` to `rank_eval` API specs ([#704](https://github.com/opensearch-project/opensearch-api-specification/pull/704))
 
 ### Removed
 - Removed unsupported `_common.mapping:SourceField`'s `mode` field and associated `_common.mapping:SourceFieldMode` enum ([#652](https://github.com/opensearch-project/opensearch-api-specification/pull/652))
@@ -48,6 +49,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Fixed `/_ingest/pipeline/{id}/_simulate` response `docs/_source` field schema ([#689](https://github.com/opensearch-project/opensearch-api-specification/pull/689))
 - Fixed `/_scripts/painless/_execute` request and response schema ([#699](https://github.com/opensearch-project/opensearch-api-specification/pull/699))
 - Fixed `fields` in `Hit` allowing primitive arrays ([#699](https://github.com/opensearch-project/opensearch-api-specification/pull/699))
+- Fixed `hits` in `rank_eval` allowing numbers ([#704](https://github.com/opensearch-project/opensearch-api-specification/pull/704))
 
 ### Changed
 - Changed `tasks._common:TaskInfo` and `tasks._common:TaskGroup` to be composed of a `tasks._common:TaskInfoBase` ([#683](https://github.com/opensearch-project/opensearch-api-specification/pull/683))

spec/schemas/_core.rank_eval.yaml

@@ -169,7 +169,7 @@ components:
         _score:
           type: number
         _type:
-          type: string
+          $ref: '_common.yaml#/components/schemas/Type'
       required:
         - _id
         - _index