"In the above example code..." when there is no above example code.

In the file/line: [csharp/concepts/generic-types/introduction.md](https://github.com/exercism/csharp/blob/c272b9d2190d9d238b51fdf4d6bdc72fad1c309a/concepts/generic-types/introduction.md?plain=1#L3)
it says "In the above example code we are instantiating a list of strings.", but there is no example code above if viewing from this link:
https://exercism.org/tracks/csharp/concepts/generic-types

I'd fork and make a PR, but I'm not sure if the line should just simply be removed, or if something was forgotten.

Example if you wanted to add it:
```C#
List strings = new List();
```