[DOC] Query field name and type in query insights documentation

[deshsidd]

What do you want to do?
As a followup to : #8173
Need to add documentation for field name and field type settings and field that is included in the query structure while grouping top b by similarity.

• Need to add documentation for the 2 settings

• Need to modify the example query shape to now show field name and field data type and mention that we take this into account for the query shape.

• 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.

*Version: List the OpenSearch version to which this issue applies, e.g. 2.14, 2.12--2.14, or all.

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