cbimport json page mentions generating a key from a nested field path

https://docs.couchbase.com/server/6.0/tools/cbimport-json.html#key-generators
mentions referencing a nested field for generating a key but this is not possible in 6.0.x.

To reference a nested field we would use "parent.child" syntax. For example to reference tha country we would use '%address.country%'. To reference a field that contains a dot in the name we escape the string using `` . For example '%`address.country`%' refers to a field named "address.country".

MB-29092 adds support for generating a key using a field nested within the JSON structure