[DOC] Add fingerprint ingest processor

[gaobinlong]

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. Provide a summary of the request and all versions that are affected.

We'll add a new ingest processor named fingerprint, it targets for 2.15.0, we should document the usage.

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.
opensearch-project/OpenSearch#13724

[gaobinlong]

Please assign this issue to me, I'll add a new documentation for it.

[vagimeli]

@gaobinlong Please tag me in the PR and I'll provide writing support.

[gaobinlong]

Hi @vagimeli , the code PR is not ready for now, we may not have enough time to complete it before the code freeze date, so could you help to remove the v2.15.0 label? Thank you!