Add hassio service descriptions (#42597)

* Add yaml for snapshot services

Adds snapshot_full and snapshot_partial service descriptions.

* fixes

Added password to full & partial.  Added name to partial.

homeassistant/components/hassio/services.yaml

@@ -73,6 +73,32 @@ host_update:
       description: Optional or it will be use the latest version.
       example: "0.3"
 
+snapshot_full:
+  description: Create a full snapshot.
+  fields:
+    name:
+      description: Optional or it will be the current date and time.
+      example: "Snapshot 1"
+    password:
+      description: Optional password.
+      example: "password"
+
+snapshot_partial:
+  description: Create a partial snapshot.
+  fields:
+    addons:
+      description: Optional list of addon slugs.
+      example: ["core_ssh", "core_samba", "core_mosquitto"]
+    folders:
+      description: Optional list of directories.
+      example: ["homeassistant", "share"]
+    name:
+      description: Optional or it will be the current date and time.
+      example: "Partial Snapshot 1"
+    password:
+      description: Optional password.
+      example: "password"
+
 supervisor_reload:
   description: Reload the Hass.io supervisor.