[DOC] Rename Search node role to Warm node role for searchable snapshots

[vinaykpud]

What do you want to do?

With the changes in opensearch-project/OpenSearch#17573, we are renaming the existing "Search" node role to "Warm" node role. Consequently, the documentation needs to be updated accordingly. This change is related to searchable snapshots: https://opensearch.org/docs/latest/tuning-your-cluster/availability-and-recovery/snapshots/searchable_snapshot/

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request.
Rename existing Node role "Search" to "Warm"

Version:
3.0

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.
https://opensearch.org/docs/latest/tuning-your-cluster/availability-and-recovery/snapshots/searchable_snapshot/