Adjust title to clarify ASP.NET Core and not .NET Core
Adjust title to clarify ASP.NET Core and not .NET Core

We had an [issue over on the .NET Core documentation](https://github.com/dotnet/docs/pull/13278) regarding Docker where someone was confused about .NET Core vs ASP.NET Core and pointed out that this article used the terms interchangeably. I wanted to submit this fix to hopefully reduce that.

I also:

1. Removed the en-us from links.
docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io