我主题写了一个设置页面，主题设置的数据保存在 configs/theme.json里

{
 
    "slogan":"The world henceforth will be run by synthesizers, people able to put together the right information at the right time, think critically about it, and make important choices wisely.",
 
    "dashboard_time":1543068693389
 
}
以上就是theme.json里的内容，但是我在主题内用 theme.slogon 无法进行调用slogan的内容，用site.slogon,theme.configs.slogon也无法调用。

设置内容到底怎么调用？