Added/updated snippets for docs (#2318)

docs/doc_examples/c96e5740b79f703c5b77e3ddc9fdf3a0.asciidoc

@@ -0,0 +1,18 @@
+// 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.indices.putIndexTemplate({
+  name: "my-index-template",
+  index_patterns: ["my-data-stream*"],
+  data_stream: {},
+  composed_of: ["my-mappings", "my-settings"],
+  priority: 500,
+  _meta: {
+    description: "Template for my time series data",
+    "my-custom-meta-field": "More arbitrary metadata",
+  },
+});
+console.log(response);
+----