Update alicloud document to add userdata (#14862)

* Update Example Usage

Delete an unnecessary option `commodity_code `.

* Update alicloud provider docs to add user_data.

website/source/docs/providers/alicloud/r/instance.html.markdown

@@ -75,6 +75,7 @@ On other OSs such as Linux, the host name can contain a maximum of 30 characters
 * `instance_charge_type` - (Optional) Valid values are `PrePaid`, `PostPaid`, The default is `PostPaid`.
 * `period` - (Optional) The time that you have bought the resource, in month. Only valid when instance_charge_type is set as `PrePaid`. Value range [1, 12].
 * `tags` - (Optional) A mapping of tags to assign to the resource.
+* `user_data` - (Optional) The user data to provide when launching the instance.
 
 ## Attributes Reference
 
@@ -93,4 +94,4 @@ The following attributes are exported:
 * `private_ip` - The instance private ip.
 * `public_ip` - The instance public ip.
 * `vswitch_id` - If the instance created in VPC, then this value is  virtual switch ID.
-* `tags` - The instance tags, use jsonencode(item) to display the value.
+* `tags` - The instance tags, use jsonencode(item) to display the value.