docs: add note to resource embedding and vertical filtering section

Adds a note about resource embedding and vertical filtering
sections when they are combined with mutation queries.

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::
+
+  It is **not** possible to perform mutations *on* related resources. When combining mutations and resource embedding, the mutation is performed first and then the related resource is returned in combination with :ref:`prefer_return`.
+
 .. _fk_join:
 
 Foreign Key Joins

docs/references/api/tables_views.rst

@@ -246,6 +246,10 @@ When certain columns are wide (such as those holding binary data), it is more ef
 
 The default is ``*``, meaning all columns. This value will become more important below in :ref:`resource_embedding`.
 
+.. note::
+
+  It is **not** possible to perform mutations *on* filtered data. When combining mutations and vertical filtering, the mutation is performed first and then the filter is applied in combination with :ref:`prefer_return`.
+
 .. _renaming_columns:
 
 Renaming Columns