Add Guideline/process/steps for adding new techniques for Hybrid Search

[navneet1v]

Description

With the launch of OpenSearch 2.10 we added support for hybrid query clause with Normalization and Score Combination processor. Given that in information retrieval space there can be many other techniques to combine and normalize the score users of the OpenSearch project might want to add new techniques for doing hybrid search.

Ask from this issue is to come up with a consistent Guideline/process/steps/benchmarks for adding new techniques for Hybrid Search.

For doing benchmarks issue is already created: #430