fix: bug usage.js

[huyunan]

throw new Error('Cannot add store with unknown type: ' + type);
^

Error: Cannot add store with unknown type: global at exports.Provider.Provider.add (D:\gitee\huyunan\nconf\lib\nconf\provider.js:130:11) at D:\gitee\huyunan\nconf\lib\nconf\provider.js:187:12 at Array.forEach () at exports.Provider.Provider.init (D:\gitee\huyunan\nconf\lib\nconf\provider.js:185:33) at new exports.Provider (D:\gitee\huyunan\nconf\lib\nconf\provider.js:25:8) at Object. (D:\gitee\huyunan\nconf\usage.js:23:16) at Module._compile (node:internal/modules/cjs/loader:1196:14) at Object.Module._extensions..js (node:internal/modules/cjs/loader:1250:10) at Module.load (node:internal/modules/cjs/loader:1074:32) at Function.Module._load (node:internal/modules/cjs/loader:909:12)