add suppor for exporting CORSConfig types

### What is the problem this feature would solve?

I want to keep the cors like this
```js
const coreConfig: CorsConfig = {
  ....
}
```

### What is the feature you are proposing to solve the problem?

add suppor for exporting CORSConfig types 
import type { CorsConfig } from '@elysiajs/cors'

### What alternatives have you considered?

_No response_