Add support for TOML files with -c, --config

[ijacobs-cpa]

I would like to add support for passing TOML files for configuration options as an alternative to providing different options in the command line.

Using -c, --config with an appropriate .toml file as an argument will be accepted as input and will replace any of the individual options in your program (lang, output). To parse the TOML file contents, I'll use the tomli TOML file parser to get the file contents.

If this solution is okay, let me know. Thanks

[Amnish04]

Sure, please go ahead with it @ijacobs-cpa .

Note: I just merged a PR with major refactoring to how markdown processing is done. Please pull the latest changes from master before starting your work.

[Amnish04]

@ijacobs-cpa Also, I think you should mostly only need to make changes to src/utils/commandline.py file for this