update to add links and add clarity on model contrcts support

adding links to clarify or add context on operations and the run operation command. also adding info on model contracts and its relation to ephemeral materialization [per feedback](https://getdbt.slack.com/archives/C0441GSRU04/p1705684634213419)

website/docs/docs/build/materializations.md

@@ -100,8 +100,9 @@ When using the `table` materialization, your model is rebuilt as a <Term id="tab
   - Ephemeral models can help keep your <Term id="data-warehouse" /> clean by reducing clutter (also consider splitting your models across multiple schemas by [using custom schemas](/docs/build/custom-schemas)).
 * **Cons:**
     * You cannot select directly from this model.
-    * Operations (e.g. macros called via `dbt run-operation` cannot `ref()` ephemeral nodes)
+    * [Operations](/docs/build/hooks-operations#about-operations) (for example, macros called using [`dbt run-operation`](/reference/commands/run-operation) cannot `ref()` ephemeral nodes)
     * Overuse of ephemeral materialization can also make queries harder to debug.
+    * Ephemeral materialization doesn't support [model contracts](/docs/collaborate/govern/model-contracts#where-are-contracts-supported).
 * **Advice:**  Use the ephemeral materialization for:
     * very light-weight transformations that are early on in your DAG
     * are only used in one or two downstream models, and