docs: add note to resource embedding and vertical filtering section

Adds a note about resource embedding and vertical filtering
sections that they are top-level operations. This resolves #4352.

Signed-off-by: Taimoor Zaeem <[email protected]>

Author: taimoorzaeem

docs/references/api/resource_embedding.rst

@@ -5,6 +5,10 @@ Resource Embedding
 
 PostgREST allows including related resources in a single API call. This reduces the need for many API requests.
 
+.. note::
+
+  Resource embedding is a **top-level** operation, which means that for mutation queries, it is performed on the affected resource **after** the mutation.
+
 .. _fk_join:
 
 Foreign Key Joins

docs/references/api/tables_views.rst

@@ -233,6 +233,10 @@ Vertical Filtering
 
 When certain columns are wide (such as those holding binary data), it is more efficient for the server to withhold them in a response. The client can specify which columns are required using the :code:`select` parameter.
 
+.. note::
+
+  Vertical filtering is a **top-level** operation, which means that for mutation queries, it is performed on the affected resource **after** the mutation.
+
 .. code-block:: bash
 
   curl "http://localhost:3000/people?select=first_name,age"