任何键都可以被引用，以 $npm_package_ 开头，并为每下一级添加下划线.

Any key can be referenced, beginning with $npm_package_ and adding an underscore for every level you go down.

示例:

{ "name": "appname", "version": "0.0.1"}

name 可以像这样访问:$npm_package_name 或 ${npm_package_name} 以在字符串中分隔

name can be access like: $npm_package_name or ${npm_package_name} to delimit within string

对于windows用户，name可以这样访问:%npm_package_name%

For windows user, name can access like: %npm_package_name%