Update metricflow-time-spine.md

clarify that the time spine models key must be placed in the `models/` directory. this pr also links to the (/reference/model-properties) page.

[slack thread](https://dbt-labs.slack.com/archives/C02NCQ9483C/p1727731703755399)

website/docs/docs/build/metricflow-time-spine.md

@@ -21,7 +21,8 @@ To see the generated SQL for the metric and dimension types that use time-spine
 - You only need to configure time-spine models that the Semantic Layer should recognize.
 - At a minimum, define a time-spine table for a daily grain.
 - You can optionally define a time-spine table for a different granularity, like hourly.
-- Note that if you don’t have a date or calendar model in your project, you'll need to create one. 
+- Note that if you don’t have a date or calendar model in your project, you'll need to create one.
+- The [`models` key](/reference/model-properties) in the time spine configuration must be placed in your `models/` directory.
 - If you're looking to specify the grain of a time dimension so that MetricFlow can transform the underlying column to the required granularity, refer to the [Time granularity documentation](/docs/build/dimensions?dimension=time_gran)
 
 If you already have a date dimension or time-spine table in your dbt project, you can point MetricFlow to this table by updating the `model` configuration to use this table in the Semantic Layer. This is a model-level configuration that tells dbt to use the model for time range joins in the Semantic Layer. 
@@ -40,7 +41,7 @@ If you don’t have a date dimension table, you can still create one by using th
 <File name="models/_models.yml">
 
 ```yaml
-models:
+[models:](/reference/model-properties)
   - name: time_spine_hourly
     time_spine:
       standard_granularity_column: date_hour # column for the standard grain of your table
@@ -56,7 +57,7 @@ models:
 ```
 </File>
 
-For an example project, refer to our [Jaffle shop](https://github.com/dbt-labs/jaffle-sl-template/blob/main/models/marts/_models.yml) example.
+For an example project, refer to our [Jaffle shop](https://github.com/dbt-labs/jaffle-sl-template/blob/main/models/marts/_models.yml) example. Note that the [`models` key](/reference/model-properties) in the time spine configuration must be placed in your `models/` directory.
 
 Now, break down the configuration above. It's pointing to a model called `time_spine_daily`. It sets the time spine configurations under the `time_spine` key. The `standard_granularity_column` is the lowest grain of the table, in this case, it's hourly. It needs to reference a column defined under the columns key, in this case, `date_hour`. Use the `standard_granularity_column` as the join key for the time spine table when joining tables in MetricFlow. Here, the granularity of the `standard_granularity_column` is set at the column level, in this case, `hour`.