[DOC] Update docs for hybrid query, add details about support of rescore feature

[martin-gaievski]

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.
Hybrid query supports rescore starting from 2.18, but the way it works is different and may mislead end user to think that it works incorrectly. We need to add simple example that will explain it and close the gap in documentation.

Version:
Applicable to 2.18 and above, can be added to latest

What other resources are available?
GH issue that asked for rescore support in hybrid query opensearch-project/neural-search#914

[kolchfa-aws]

Closed by PR #11941