Adding deletion and update info

Author: sadick254

README.md

@@ -154,6 +154,20 @@ The resulting bound array stored in `vm.items` will be:
   }
 ]
 ```
+Therefore to delete or update an item: first you have to obtain a reference to the '.key' property or the item object. In your Vue instance you could add 
+ ``` js
+ //pass '.key' property from html
+ vm.deleteItem = function(key) {
+   var ref = db.ref('items/'+key)
+   ref.remove()
+ }
+ //pass in item object from html
+ vm.updateItem = function(item) { 
+   var key = item['.key']
+   var ref = db.ref('items/'+key)
+   ref.set(item)
+ } 
+ ```
 
 ## Contributing