Added/updated snippets for docs (#2318)

docs/doc_examples/1cea60c47d5c0e150b4c8fff4cd75ffe.asciidoc

@@ -0,0 +1,32 @@
+// 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.ingest.simulate({
+  pipeline: {
+    processors: [
+      {
+        script: {
+          description: "Set index based on `lang` field and `dataset` param",
+          lang: "painless",
+          source:
+            "\n            ctx['_index'] = ctx['lang'] + '-' + params['dataset'];\n          ",
+          params: {
+            dataset: "catalog",
+          },
+        },
+      },
+    ],
+  },
+  docs: [
+    {
+      _index: "generic-index",
+      _source: {
+        lang: "fr",
+      },
+    },
+  ],
+});
+console.log(response);
+----