[DOCS] Expands GET DFA stats API docs with new phases (#56407)

Co-authored-by: Lisa Cawley <lcawley@elastic.co>

docs/reference/ml/df-analytics/apis/get-dfanalytics-stats.asciidoc

@@ -478,7 +478,17 @@ include::{docdir}/ml/ml-shared.asciidoc[tag=node-transport-address]
 =====
 `phase`:::
 (string) Defines the phase of the {dfanalytics-job}. Possible phases: 
-`reindexing`, `loading_data`, `analyzing`, and `writing_results`.
+* `reindexing`, 
+* `loading_data`, 
+* `computing_outliers` (for {oldetection} only),
+* `feature_selection` (for {regression} and {classification} only),
+* `coarse_parameter_search` (for {regression} and {classification} only),
+* `fine_tuning_parameters` (for {regression} and {classification} only),
+* `final_training` (for {regression} and {classification} only),
+* `writing_results`.
++
+To learn more about the different phases, refer to
+{ml-docs}/ml-dfa-phases.html[How a {dfanalytics} job works].
     
 `progress_percent`:::
 (integer) The progress that the {dfanalytics-job} has made expressed in