Typescript support

### Expected Behaviour
Should be able to use in context with Typescript

### Actual Behaviour
Does not work, errors when specifying Model attributes as not found

### Reproduce Scenario (including but not limited to)
Try running in a typescript enabled project

#### Steps to Reproduce
Write any example model inside the typescript contexts

#### Platform and Version
Any

首先，在一个启用 TypeScript 的项目中，使用 issue 中描述的示例模型重现该问题。追踪模型属性为何被报告为缺失，然后验证模型在 TypeScript 上下文中可以正常工作且不会出现这些错误。

由索引模型根据 Issue 内容生成。