What type of files can be signed using signtool.exe?

It should be added what kind of files can be signed using `signtool.exe`.

You cannot sign pdf, txt, images, etc, but exe, dll, application, ps files etc...
A comprehensive list would be nice.

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#### Document Details

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* ID: 72a4dbac-a145-e79f-121d-3d8df67552b1
* Version Independent ID: 9ea61916-a9db-f23e-4c43-edc06650483d
* Content: [SignTool.exe (Sign Tool) - .NET Framework](https://learn.microsoft.com/en-us/dotnet/framework/tools/signtool-exe)
* Content Source: [docs/framework/tools/signtool-exe.md](https://github.com/dotnet/docs/blob/main/docs/framework/tools/signtool-exe.md)
* Product: **dotnet-framework**
* GitHub Login: @gewarren
* Microsoft Alias: **gewarren**

從 docs/framework/tools/signtool-exe.md 開始，這是連結的 SignTool.exe 頁面所對應的文件來源。確認 SignTool 支援哪些檔案類型，然後新增一份完整清單，區分支援的檔案與不支援的範例；文件應清楚回答哪些內容可以簽署。

由索引模型根據 Issue 內容生成。