WIP: Update cloud.markdown (#4015)

* Update cloud.markdown

* Update cloud.markdown

source/_components/cloud.markdown

@@ -63,4 +63,26 @@ alexa:
           type: list
 {% endconfiguration %}
 
+### {% linkable_title Possible values for customize %}
+
+| Attribute | Description |
+| --------- | ----------- |
+| `alexa_hidden` | Hide the entity from the Alexa smart home devices.
+| `alexa_name` | Defines name of the entity for a Alexa smart home device. Useful if you have an entity with a friendly name in a local language that you want to access using an English sounding name.
+| `alexa_description` | The description of the device in the Alexa smart home device list.
+| `alexa_display_categories` | Set displayCategories, useful for things like media_player (TV/SPEAKERS) or scene (ACTIVITY_TRIGGER/SCENE_TRIGGER). More info can be found [here](https://developer.amazon.com/docs/device-apis/alexa-discovery.html#display-categories).
+
+### {% linkable_title Available domains %}
+Currently, the following domains are available to be used with Alexa:
+- alert
+- automation
+- cover
+- light
+- fan (supports on/off and set speed)
+- group
+- lock (lock and unlock, but unlock is untested as Amazon has disabled unlock for now)
+- media_player (play, pause, stop, set volume, adjust volume, next track and previous track)
+- scene
+- switch
+
 [alexa skill]: https://alexa.amazon.com/spa/index.html#skills/dp/B0772J1QKB/?ref=skill_dsk_skb_sr_2