[DOCS] Updates results_field description in the inference processor docs (#58554)

docs/reference/ingest/processors/inference.asciidoc

@@ -42,7 +42,7 @@ Regression configuration for inference.
 
 `results_field`::
 (Optional, string)
-include::{es-repo-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field]
+include::{es-repo-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]
 
 `num_top_feature_importance_values`::
 (Optional, integer)
@@ -65,7 +65,7 @@ include::{es-repo-dir}/ml/ml-shared.asciidoc[tag=inference-config-classification
 
 `results_field`::
 (Optional, string)
-include::{es-repo-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field]
+include::{es-repo-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]
 
 `top_classes_results_field`::
 (Optional, string)

docs/reference/ml/ml-shared.asciidoc

@@ -743,6 +743,12 @@ The field that is added to incoming documents to contain the inference
 prediction. Defaults to `predicted_value`.
 end::inference-config-results-field[]
 
+tag::inference-config-results-field-processor[]
+The field that is added to incoming documents to contain the inference
+prediction. Defaults to the `results_field` value of the {dfanalytics-job} that was
+used to train the model, which defaults to `<dependent_variable>_prediction`.
+end::inference-config-results-field-processor[]
+
 tag::influencers[]
 A comma separated list of influencer field names. Typically these can be the by, 
 over, or partition fields that are used in the detector configuration. You might