[Bug Report] egg-mongoose config 缺少类型定义

[SliverYuki]

What happens?

egg-mongoose 插件 config 缺少某些字段的类型定义，例如

// config.default.ts

config.mongoose = {
   loadModel: false,
}

复现步骤，错误日志以及相关配置

错误日志: config/config.default.ts(35,5): error TS2322: Type '{ loadModel: boolean; }' is not assignable to type 'PowerPartial<{ url?: string | undefined; options?: ConnectionOptions | undefined; client?: MongooseConfig | undefined; clients?: { [key: string]: MongooseConfig; } | undefined; }>'. Object literal may only specify known properties, and 'loadModel' does not exist in type 'PowerPartial<{ url?: string | undefined; options?: ConnectionOptions | undefined; client?: MongooseConfig | undefined; clients?: { [key: string]: MongooseConfig; } | undefined; }>'.

相关环境信息

• 操作系统：macOS Catalina 10.15.4
• Node 版本：v10.19.0
• Egg 版本：v2.26.0
• egg-mongoose 版本: v3.2.0

[SliverYuki]

loadModel 方法同样缺少类型定义

await this.app.mongoose.loadModel() 
// Property 'loadModel' does not exist on type 'typeof import("mongoose")'

[SliverYuki]

createInstanceAsync 方法也缺少

const dbInstance = await this.app.mongooseDB.createInstanceAsync(dbConfig)
// Property 'createInstanceAsync' does not exist on type 'Connection | MongooseSingleton'.

建议梳理一下然后加上所有的类型定义，不胜感激