Multiple issues with the CountMillionCharacters family of programs.

The README states:

CountMillionCharacter.py And CountMillionCharacter2.0.py - Gets character count of a text file.

Yet CountMillionCharacter2.0.py seems to be counting words, and says as much.

There is also a folder CountMillionCharacters-Variations which contains a third version of the program, named variation1.py. It would obviously be good to decide on what the CountMillionCharacters programs are meant to do, and the versions/variations to create.

For now, I think there are some changes to be made in at least two of the versions:

• For one, dropping the use of .upper(), or at least replacing it with .casefold().
• The use of .get() in variation1.py could be replaced with a defaultdict.
• variation.py contains a camelCase variable name.
• CountMillionCharacter.py uses exit() for seemingly no good reason.
• CountMillionCharacter.py [calls main()] instead of exiting the program or using a loop.
• ...and more.

I will try to tweak the code and create a pull request (or a few).

Start with the README entries for CountMillionCharacter.py and CountMillionCharacter2.0.py, then compare those files with CountMillionCharacters-Variations/variation1.py. Decide and document the intended behavior and version structure before changing the listed case handling, defaultdict usage, variable naming, and program-exit flow; done means the programs and README agree.