Update and rename add-item to add-item.md

Added property editors

Author: mr-shellychauhan

13/umbraco-commerce/how-to-guides/add-item renamed to 13/umbraco-commerce/how-to-guides/add-item.md

@@ -10,6 +10,13 @@ You will need the front end to be set up to allow an item to be added to the car
 
 Create a new Document Type with the template. Call it **Product Page** with the following property aliases: `productTitle`, `productDescription`, `price`, `stock`.
 
+The following property editors are recommeded to be used for the above:
+
+`productTitle`: TextString
+`productDescription`: TextArea
+`price`: Umbraco Commerce Price
+`stock`: Umbraco Commerce Stock
+
 The Product Page template can be implemented as shown below.
 
 ```csharp