Missing parallel samples

**Issue description**

Many blog posts and websites still refer to the old code gallery location for the parallel samples https://devblogs.microsoft.com/pfxteam/samples-for-parallel-programming-with-the-net-framework-4/

I've noticed that _some_ samples can be found on the new gallery, however [**many are missing**](https://devblogs.microsoft.com/pfxteam/a-tour-through-the-parallel-programming-samples-for-net-4/). I managed to find a repository on github that contained all the samples, which I promptly forked myself. You can find it over [here](https://github.com/CrispyDrone/parallel).

It would be great to have these samples included in this repository together with the other parallel samples that are already there. They might require an update to dotnet core since many of them use WPF.