Catalog OS known issues

New OS versions may expose behavior changes that can cause existing apps to break. Users often log issues when they experience such problems, in particular for the container images we ship, which deliver the OS and .NET as a single artifact. In many cases, users cannot determine the root cause and look to us for support. Tracking issues often include user-provided workarounds (endorsed by us or not) and those can prove useful. We have a responsibility to make it easy to find these issues so that users who come later can use previous findings to self-diagnose and -address problems.

We will document OS issues in dotnet/core (this repo).

These issues are distinct from [.NET compatibility breaks](https://learn.microsoft.com/dotnet/core/compatibility/), which users observe upgrading from .NET version n to .NET version n+1 (or more than +1). When a user observes a break in behavior when upgrading from OS version n to OS version n + 1, we consider that an OS known issue. In some cases, it makes sense for .NET to adapt to those changes and in other cases not.

Related: https://github.com/dotnet/dotnet-docker/issues/6073