[Feature Request] Add TODO for Updating API Spec

[kkhatua]

Is your feature request related to a problem? Please describe

With the introduction of OpenSearch API Specification for generating client libraries and documentation in multiple languages (See: https://github.com/opensearch-project/opensearch-api-specification?tab=readme-ov-file#welcome), it is possible that new features might miss out on defining the APIs, leading in gaps in what the generated clients for exotic languages can support.

Describe the solution you'd like

It would be good to have the pull request template include an item in its checklist for updating the API specs as a precondition to committing the feature.

Related component

Clients

Describe alternatives you've considered

N/A

Additional context

No response