feat: parse CLI args using getopt

[cybardev]

Description

Currently the script uses very basic pattern matching to parse command-line arguments. We want to use getopt instead.

Changes Requested

• use getopt to parse command-line arguments

Tests

• [ ] ran with no args
• [ ] ran with -h flag
• [ ] ran with --help flag
• [ ] ran with short flag for each animal
  • [ ] ran with each eye option
• [ ] ran with long flag for each animal
  • [ ] ran with each eye option

Reviewers

• N/A