Change dot notation in add column documentation to tuple

mkdocs/docs/api.md

@@ -951,8 +951,12 @@ Using `add_column` you can add a column, without having to worry about the field
 with table.update_schema() as update:
     update.add_column("retries", IntegerType(), "Number of retries to place the bid")
     # In a struct
-    update.add_column("details.confirmed_by", StringType(), "Name of the exchange")
+    update.add_column("details", StructType())
+
+with table.update_schema() as update:
+    update.add_column(("details", "confirmed_by"), StringType(), "Name of the exchange")
 ```
+A complex type must exist before columns can be added to it. Fields in complex types are added in a tuple.
 
 ### Rename column
 
@@ -961,20 +965,21 @@ Renaming a field in an Iceberg table is simple:
 ```python
 with table.update_schema() as update:
     update.rename_column("retries", "num_retries")
-    # This will rename `confirmed_by` to `exchange`
-    update.rename_column("properties.confirmed_by", "exchange")
+    # This will rename `confirmed_by` to `processed_by` in the `details` struct
+    update.rename_column(("details", "confirmed_by"), "processed_by")
 ```
 
 ### Move column
 
-Move a field inside of struct:
+Move order of fields:
 
 ```python
 with table.update_schema() as update:
     update.move_first("symbol")
+    # This will move `bid` after `ask`
     update.move_after("bid", "ask")
-    # This will move `confirmed_by` before `exchange`
-    update.move_before("details.created_by", "details.exchange")
+    # This will move `confirmed_by` before `exchange` in the `details` struct
+    update.move_before(("details", "confirmed_by"), ("details", "exchange"))
 ```
 
 ### Update column
@@ -1006,6 +1011,8 @@ Delete a field, careful this is a incompatible change (readers/writers might exp
 ```python
 with table.update_schema(allow_incompatible_changes=True) as update:
     update.delete_column("some_field")
+    # In a struct
+    update.delete_column(("details", "confirmed_by"))
 ```
 
 ## Partition evolution