Improve command line interface by adding argparse functionality

[ortk95]

Adds planetmapper --help and planetmapper --version to CLI

Closes #91

Pull request checklist

• [x] Add a clear description of the change
• [x] Add any new tests needed
• [x] Run spell check on new text visible to user (documentation, GUI etc.)
• [ ] Check any changes to requirements.txt are reflected in setup.py and conda-forge feedstock
• [ ] Check code passes CI checks (run run_ci.sh or check GitHub Actions)

See CONTRIBUTING.md for more details.

[coveralls]

Pull Request Test Coverage Report for Build 7448159096

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.002%) to 99.508%

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Totals
Change from base Build 7409660349:	0.002%
Covered Lines:	2801
Relevant Lines:	2815

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💛 - Coveralls