[checkbox][docs] fixes doc table extra column cell (#6995)

components/checkbox/index.en-US.md

@@ -20,7 +20,7 @@ Checkbox.
 | checked | Specifies whether the checkbox is selected. | boolean | false |
 | defaultChecked | Specifies the initial state: whether or not the checkbox is selected. | boolean | false |
 | onChange | The callback function that is triggered when the state changes. | Function(e:Event) | - |
-| disabled | Disable checkbox | boolean | | false| 
+| disabled | Disable checkbox | boolean | false| 
 
 ### Checkbox Group
 
@@ -30,4 +30,4 @@ Checkbox.
 | value | Used for setting the currently selected value. | string[] | [] |
 | options  | Specifies options | string[] | [] |
 | onChange | The callback function that is triggered when the state changes. | Function(checkedValue) | - |
-| disabled | Disable all checkboxes | boolean | | false |
+| disabled | Disable all checkboxes | boolean | false |