[Suggestion] Use submodule for third-party code

[a1ive]

如题，用 git submodule 和 patch 文件是不是更好一些，比如 EDK2/iPXE/GRUB 之类的代码。

[ventoy]

是的，其实是我对git操作不是很熟悉☹，后面我会好好整理一下。

[Sporesirius]

With the concept of submodules you can then easily use github actions for autobuilds and tests. @ventoy your solution for a multiboot stick is very nice 👍 and hi @a1ive thanks that you starred that project :D