Running without a config.yaml file

[quic-mathbern]

It would be nice if ctracker could be run out-of-the-box without a config.yaml file. Some sane defaults would have to be configured. Perhaps only tracking individual contributors and not orgs (Relates to #5 ). Or even use the email domains as default orgs. (In either case, the orgs_files field map could be ignored, together with any metrics associated with it).

Using a default of individual vs org could also be toggled by a CLI option.

[github-actions]

This issue is stale. Add a nice message, can mention maintainers or maintainer team to draw attention