Improve docs/tutorial/SearchService.md for all aspects of work with nested arrays search (for not familiar users) [GONRG-2710]

!121 (merged)

• As there are more than one way to index nested object, we should put the documentation on each type and what queries can done.
• We may also have to tell users where to look for required types in schema. Please expect that Search services users may not be familiar with other services.

See thread: !121 (comment 50336) for @nthakur comments https://jiraeu.epam.com/browse/GONRG-2710