feat: finish tests & docs

README.md

@@ -300,10 +300,20 @@ #### Check if cart is empty: **Cart::isEmpty()**
 
 #### Clearing the Cart: **Cart::clear()**
 
+This clears all items and conditions from the cart.
+
 ```php
 Cart::clear();
 ```
 
+#### Clearing the cart items only: **Cart::clearItems()**
+
+This clears all items, but keeps the conditions (useful for when you want to keep the conditions but remove the items)
+
+```php
+Cart::clearItems();
+```
+
 ### Conditions
 
 Conditions are very useful for adding things like discounts, taxes, shipping, etc.