create a cli interface for this Exiftool package

[mattduffy]

Add a cli interface to this package that lets the user issue exiftool commands through this simplified wrapper. The most basic invocation would be like:

bash$ myExiftool /path/to/my/photo.heic

This would use the default shortcut stored in the exiftool.config file associated with the package.

Specifying a different shortcut stored in the exiftool.config file would be:

bash$ myExiftool SpecialShortcut /path/to/my/photo.heic

Adding new shortcuts to the exiftool.config file:

bash$ myExiftool addNewShortcut ['File:MIMEType', 'EXIF:Make', 'Exif:Model']