OctoPrint-CalibrationTools/extras

Currently Cookiecutter generates the following helpful extras to this folder:

CalibrationTools.md
    Data file for plugins.octoprint.org. Fill in the missing TODOs once your
    plugin is ready for release and file a PR as described at
    http://plugins.octoprint.org/help/registering/ to get it published.

This folder may be safely removed if you don't need it.