[DOCS] Updated target_field description of the json ingest processor (#61968)
[DOCS] Updated target_field description of the json ingest processor (#61968)

Co-authored-by: Dan Hermann <bf1bf3ea0c00483ec99d4d21c5a72a38f8a7489d@users.noreply.github.com>
GlenRSmith/elasticsearch,nknize/elasticsearch,GlenRSmith/elasticsearch,robin13/elasticsearch,robin13/elasticsearch,robin13/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch,nknize/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch