export without -u, -p, -o, -r arguments

[sergey-s-betke]

When GitReleaseManager run from directory with git repository, for export read-only public access is enough. GitHub repository - from remote repositories for current (in current directory) repository. As https://github.com/GitTools/GitReleaseNotes...

[gep13]

@sergey-s-betke I will have to check whether Octokit allows the creation of an anonymous API call. I will check, and let you know.