Bug - Action does not work on shallow clones

[aormsby]

Currently, a full repo clone is required for this action to complete successfully. (This requires the fetch-depth: 0 option during the action/checkout step if following the sample workflow pattern.) Ideally, the action should also work with shallow clones, but there have been some difficulties.

For the full explanation of the problem, please see https://github.com/aormsby/hugo-deploy-to-pages/wiki/Git-Shallow-Clone-Challenge