Suggest updating config if upstream remote not found

[gibfahn]

Currently if you have an upstream remote not called upstream, and you choose to try to update from the remote branch, then git-node just errors out.

It should be possible to detect that the specified remote isn't defined in this directory, have the user choose their upstream name, and then run ncu-config set upstream <chosen name> for them before continuing.

? Do you want to try reset the branch to upstream/master? [Y/n] 
⠋ Bringing upstream/master up to date...fatal: 'upstream' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

[github-actions]

This issue is stale because it has been open many days with no activity. It will be closed soon unless the stale label is removed or a comment is made.

[codebytere]

Resolved by #426