Add visible by default property to base Entity (#1301)

docs/core/entity.md

@@ -84,6 +84,7 @@ The following properties are also available on entities. However, they are for a
 | Name                            | Type    | Default | Description                                                                                                                                                                                                           |
 | ------------------------------- | ------- | ------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | entity_registry_enabled_default | boolean | `True`  | Indicate if the entity should be enabled or disabled when first added to the entity registry. This includes fast-changing diagnostic entities or, assumingly less commonly used entities. For example, a sensor exposing RSSI or battery voltage should typically be set to `False`; to prevent unneeded (recorded) state changes or UI clutter by these entities. |
+| entity_registry_visible_default | boolean | `True`  | Indicate if the entity should be hidden or visible when first added to the entity registry. |
 | force_update                    | boolean | `False` | Write each update to the state machine, even if the data is the same. Example use: when you are directly reading the value from a connected sensor instead of a cache. Use with caution, will spam the state machine. |
 | icon                            | icon    | `None`  | Icon to use in the frontend. Icons start with `mdi:` plus an [identifier](https://materialdesignicons.com/). You probably don't need this since Home Assistant already provides default icons for all entities according to its `device_class`. This should be used only in the case where there either is no matching `device_class` or where the icon used for the `device_class` would be confusing or misleading. |