Refactor to clistyle.sh

Updates:
- ground up refactor
- remamed to `clistyle.sh`
- added usage via `./clistyle.sh`
- added passing tests using `CLIunit.sh`
  - run via: `make` or `make test`

Outstanding:
- installer (see CLIunit.sh for example)
- rename repo
- animations
- updating icons to use codes

Known issues:
- elements (e.g. bold, italics, etc.) aren't working for me