Make default registry a configuration item

[cupdike]

I am reporting:

• feature request

Consider making the default registry a configuration item rather than embedding it in the code. That is, put datbase.org into a config file so it can easily be changed rather than having to modify multiple files. This would help make it easier to deploy for a private network to alleviate concerns about accidental data leakage.

[joehand]

@cupdike yes, good idea! We aimed to make it easy to configure in the CLI but not the code itself.

Once you run dat login my-registry.com it will use that by default. But its not configurable in the code itself at the moment.