Add a workflow for documenting features

[VachaShah]

Is your feature request related to a problem?
Humans have to remember to document features, or at least to open issues in documentation-website for new features/changes to be documented. This is a manual process, e.g. opensearch-project/OpenSearch#1711 (comment)

What solution would you like?
Add a workflow for creating issues in the documentation-website repo whenever a label needs-documentation is added on a PR. Refer: opensearch-project/OpenSearch#2929

What alternatives have you considered?
Create issues manually in the documentation-website whenever a feature needs to be documented.

Do you have any additional context?
Add any other context or screenshots about the feature request here.