Update README.md

README.md

@@ -197,7 +197,7 @@ This is still experimental and more customizations are coming.
 | `entity` | string | **Required** (and soon optional) | Any entity that can be on/off or true/false, any media player, cover or light | An entity for the state of the button |
 | `button_type` | string | **Required** | `custom` | The behavior of your button |
 | `name` | string | Optional | Any string | A name for your button, if not defined it will display the entity name |
-| `icon` | string | Optional | Any `mdi:` icon | An icon for your button, if not defined it will display the entity icon |
+| `icon` | string | Optional | Any `mdi:` icon or a link to a square image | An icon for your button, if not defined it will display the entity icon or the `entity-picture` |
 | `tap_action` | object | Optional | See [actions](#tap-double-tap-and-hold-actions) | Define the type of action on button click, if undefined, `more-info` will be used. |
 | `double_tap_action` | object | Optional | See [actions](#tap-double-tap-and-hold-actions) | Define the type of action on button double click, if undefined, `toggle` will be used. |
 | `hold_action` | object | Optional | See [actions](#tap-double-tap-and-hold-actions) | Define the type of action on button hold, if undefined, `more-info` will be used. |