netbox_tenant: Fixes example to match argspec (#509)

Author: joewesch

plugins/modules/netbox_tenant.py

@@ -130,7 +130,7 @@
         netbox_token: thisIsMyToken
         data:
           name: Tenant ABC
-          group: Very Special Tenants
+          tenant_group: Very Special Tenants
           description: ABC Incorporated
           comments: '### This tenant is super cool'
           slug: tenant_abc