[Docs] Storage ref docs (#1985)

docs/docs/reference/store.md

@@ -0,0 +1,6 @@
+# Storage
+
+::: langgraph.store.base
+    
+
+::: langgraph.store.postgres

docs/mkdocs.yml

@@ -206,6 +206,7 @@ nav:
   - Reference:
       - Graphs: reference/graphs.md
       - Checkpointing: reference/checkpoints.md
+      - Storage: reference/store.md
       - Prebuilt Components: reference/prebuilt.md
       - Channels: reference/channels.md
       - Errors: reference/errors.md

libs/checkpoint/langgraph/store/base/__init__.py

@@ -14,7 +14,7 @@ class Item:
 
     Args:
         value (dict[str, Any]): The stored data as a dictionary. Keys are filterable.
-        (str): Unique identifier within the namespace.
+        key (str): Unique identifier within the namespace.
         namespace (tuple[str, ...]): Hierarchical path defining the collection in which this document resides.
             Represented as a tuple of strings, allowing for nested categorization.
             For example: ("documents", 'user123')