Added/updated snippets for docs (#2318)

docs/doc_examples/468f7ec42cdd8287cdea3ec1cea4a514.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.update({
+  index: "my-index-000001",
+  id: 1,
+  script: {
+    source:
+      "if (ctx._source.tags.contains(params['tag'])) { ctx._source.tags.remove(ctx._source.tags.indexOf(params['tag'])) }",
+    lang: "painless",
+    params: {
+      tag: "blue",
+    },
+  },
+});
+console.log(response);
+----