Refactor Package Name for Clarity (from main to clipper or clipboardtool)

[supitsdu]

The current package name (main) is generic and doesn't reflect the purpose of clipper. Renaming it to something more descriptive, like clipper or clipboardtool, would enhance code organization and make the project's structure more intuitive.

Tasks:

1. Rename the main package to either clipper or clipboardtool.
2. Update any references to the package in import statements and documentation.

[supitsdu]

Hey everyone,

Just a quick update on the refactoring work in progress. I was able to dedicate some of my free time to make headway on this project.

Summary of Changes:

• Renamed Package: The main package has been renamed to clipper, which is more aligned with the project's purpose.
• Interfaces: Introduced ContentReader and ClipboardWriter interfaces in clipper.go to improve flexibility and testability.
• Options Handling: Created the options package (options.go) to centralize command-line argument parsing and configuration management.
• Deleted Old Files: Removed the old main.go and main_test.go files as their functionality has been migrated.

I'm currently working on updating the unit tests to reflect these changes. Once those are finalized, I'll submit a pull request for review.

Feel free to take a peek at the changes and share any feedback or suggestions you might have. Contributions are always appreciated!