preload.js如何加载？
https://www.electronjs.org/zh/docs/latest/tutorial/context-isolation#%E4%B8%8Etypescript%E4%B8%80%E5%90%8C%E4%BD%BF%E7%94%A8
Reference
Announcing TypeScript support in Electron
How to add my own typescript classes in Electron project
