安装 overtrue/laravel-lang 语言扩展包注意选择版本号

因为当前课程 laravel 版本号为 8.x，直接输入课程命令可能会有错误：

 $ composer require overtrue/laravel-lang

根据 overtrue/laravel-lang 的说明，需要在后面加上：~5.0

Laravel version	Composer command
Laravel 9.x	`composer require overtrue/laravel-lang:~6.0`
Laravel 7.x-8.x	`composer require overtrue/laravel-lang:~5.0`
Laravel 6.x	`composer require overtrue/laravel-lang:~4.0`
Laravel 5.8	`composer require overtrue/laravel-lang:~3.0`
Laravel 5.1-5.7	`composer require overtrue/laravel-lang:~2.0`
Laravel 5	`composer require overtrue/laravel-lang:~1.0`