[FEATURE]: Add TypeScript definitions for custom bundles

Since plotly.js v4 includes built-in TypeScript definitions, it would be great if custom bundles could also generate matching TypeScript definitions.

This would make custom bundles safer and easier to use in TypeScript projects.

In my case, I sometimes use a custom bundle to test newly developed features before they are released. However, the custom bundle does not include corresponding type definitions, so I have to rely on the types from the latest released version.

This can lead to missing or mismatched types, especially when the custom bundle includes new APIs or features that are not yet available in the released version.

首先追踪自定义 bundle 的生成方式，以及内置的 TypeScript 定义如何包含在 plotly.js v4 中。定义自定义 bundle 的预期匹配输出，包括尚未发布功能中的 API，并验证生成的定义能够反映该 bundle。