Fix index template step in Set up a TSDS (#3945)

Fixes #3914

- Move lifecycle object to the right place in the example
- Clarify intro text

Author: marciw

manage-data/data-store/data-streams/set-up-tsds.md

@@ -63,7 +63,6 @@ PUT _ilm/policy/my-weather-sensor-lifecycle-policy
         }
       }
       // Additional phases (warm, cold, delete) as needed
-      }
     }
   }
 }
@@ -85,10 +84,10 @@ The structure of a time series data stream is defined by an index template. Crea
         - To define dimensions dynamically, you can use a pass-through object. For details, refer to [Defining sub-fields as time series dimensions](elasticsearch://reference/elasticsearch/mapping-reference/passthrough.md#passthrough-dimensions).
     - **Metrics:** To define a metric, use the `time_series_metric` mapping parameter. For details, refer to [Metrics](/manage-data/data-store/data-streams/time-series-data-stream-tsds.md#time-series-metric).
     - **Timestamp** (optional): Define a `date` or `date_nanos` mapping for the `@timestamp` field. If you don't specify a mapping, {{es}} maps `@timestamp` as a `date` field with default options.
-    -  {applies_to}`serverless: unavailable` {applies_to}`stack: ga` **Lifecycle management**: For {{stack}}, include lifecycle settings to enable automatic rollover and prevent indices from growing too large. 
-        - Set `"lifecycle": { "enabled": true }`. 
-        - If you created an ILM policy in [step 1](#tsds-ilm-policy), reference it with `index.lifecycle.name`.
-    - **Other settings**  (optional): Additional index settings, such as [`index.number_of_replicas`](elasticsearch://reference/elasticsearch/index-settings/index-modules.md#dynamic-index-number-of-replicas), for the data stream's backing indices.
+    - {applies_to}`serverless: unavailable` {applies_to}`stack: ga` **Lifecycle management**: If you're using {{stack}}, define a lifecycle to enable automatic rollover and prevent indices from growing too large.
+        - Add a `lifecycle` object and specify `"enabled": true`. 
+        - If you created an ILM policy in [step 1](#tsds-ilm-policy), reference it in the settings with `index.lifecycle.name`.
+    - **Settings** (optional): Define any relevant index settings, such as [`index.number_of_replicas`](elasticsearch://reference/elasticsearch/index-settings/index-modules.md#dynamic-index-number-of-replicas), for the data stream's backing indices.
 - **Priority:** Set the priority higher than `200` to avoid [collisions](/manage-data/data-store/templates.md#avoid-index-pattern-collisions) with built-in templates.
 
 **Example index template PUT request:**
@@ -101,10 +100,10 @@ PUT _index_template/my-weather-sensor-index-template
   "template": {
     "settings": {
       "index.mode": "time_series",
-      "index.lifecycle.name": "my-lifecycle-policy", <1>
-      "lifecycle": { 
-        "enabled": true <2>
-      }
+      "index.lifecycle.name": "my-lifecycle-policy" <1>
+    },
+    "lifecycle": { 
+      "enabled": true <2>
     },
     "mappings": {
       "properties": {