[DOC] Document the need to re-index Romanian documents for OpenSearch 3.x

[gweyeratlassian]

What do you want to do?

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

Tell us about your request.

Lucene 10 requires Romanian documents to be re-indexed, see https://github.com/apache/lucene/blob/main/lucene/MIGRATE.md#romanian-analysis. This is not mentioned in OpenSearch 3.x breaking changes.

Version:

OpenSearch 3.x.

What other resources are available?

https://github.com/apache/lucene/blob/main/lucene/MIGRATE.md#romanian-analysis