Added/updated snippets for docs (#2318)

docs/doc_examples/388d3eda4f792d3fce044777739217e6.asciidoc

@@ -0,0 +1,19 @@
+// This file is autogenerated, DO NOT EDIT
+// Use `node scripts/generate-docs-examples.js` to generate the docs examples
+
+[source, js]
+----
+const response = await client.ml.evaluateDataFrame({
+  index: "animal_classification",
+  evaluation: {
+    classification: {
+      actual_field: "animal_class",
+      predicted_field: "ml.animal_class_prediction",
+      metrics: {
+        multiclass_confusion_matrix: {},
+      },
+    },
+  },
+});
+console.log(response);
+----