[DOC] Missing documentation on Search

[hdhalter]

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.

Scripting (6 pages), Painless scripting guide and specifications (44 pages), Painless API (27 pages), collapse search results, filter search results, near real-time search, retrieve inner hits, retrieve selected fields, search multiple data streams and indices, search shard routing,

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.