Add links to examples

[idg10]

In at least some of these examples, I understand these patterns are used in Microsoft frameworks, e.g.:

DotNetCodingPatterns/1.md

Line 11 in f77b54f

This pattern is used in **Microsoft.Extensions.\*** and in **Microsoft.AspNetCore.\***. The idea is that you can use a generic type as a factory instead of a function. The type argument is the

I would find it really helpful if these cases could have links to one or more examples. Seeing a pattern described purely in the abstract can be tricky to grasp. If we can see a specific example of where it has been used, that can make it a lot easier to grasp the rationale.