[feature] - using a private registry, dynamic CLI option

[cvega]

We have a customer that is not able to connect to ghcr.io directly for security purposes but does proxy through artifactory within their own private network to be able to get at containers within ghcr.

They would like the ability to have a dynamic registry option that enables them to modify the location of the container. We're going to take a look at the code below and see if this is something services might be able to help with in the interim.

public class App
{
    private const string ActionsImporterImage = "actions-importer/cli";
    private const string ActionsImporterContainerRegistry = "ghcr.io";
...
    username ??= Environment.GetEnvironmentVariable("GHCR_USERNAME");
    password ??= Environment.GetEnvironmentVariable("GHCR_PASSWORD");

Worst case scenario, we may show them how to build this using a custom url to see if it's something they can move forward with.