usability request: improve error message when missing requirement (when no verbs/arguments match)

We've used your library a long time, it's very helpful thanks.

I wanted to request that you consider checking for linq errors and not throwing an exception but providing an error.

The best example is this one which I am seeing a lot ( nuget version: 2.8.0 )

System.InvalidOperationException : Sequence contains no elements

This has happened both for coding errors (copying an option class and forgetting to rename verb) but also for user/usage errors, when some arguments don't match.

This is coming from Linq, it would be more helpful to diagnose them if you could check for requirements prior to parsing a verb or argument and return relevant error.

首先追蹤在 verb 或 argument 解析期間引發「Sequence contains no elements」的 LINQ 路徑。檢視目前如何處理缺少的需求和不相符的引數，然後針對這兩種情況定義並測試適當的診斷錯誤，以取代該例外。

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