Caching and general improvements

[caffeine-addictt]

What type of PR is this? (check all applicable)

• [x] Refactor
• [x] Feature
• [x] Bug Fix
• [x] Optimization
• [x] Breaking Change
• [x] Documentation Update

Description

• Only YAML is accepted as the config file format
• Caching file
• Caching commands
• Resolving non-urls from cache in get command
• Standardizing help arguments
• Resolving file extensions from Content-Type header in get command
• Better flag/option validation & help

Related Tickets & Documents

• Closes #37

QA Instructions, Screenshots, Recordings

Please replace this line with instructions on how to test your changes, a note on the devices and browsers this has been tested on, as well as any relevant images for UI changes.

Added/updated tests?

We encourage you to keep the code coverage percentage at 80% and above.

• [ ] Yes
• [ ] No, and this is why: please replace this line with details on why tests have not been included
• [x] I need help with writing tests

[optional] Are there any post deployment tasks we need to perform?

Checklist

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.