Support Multiple JSON Files or URLs

[krishana7911]

Description:

Enhance the CLI to accept multiple JSON files or API URLs for conversion in a single run. This allows users to combine results into one table or create separate outputs.

Tasks:

• Add support for --file and --url to accept multiple values (e.g., --file file1.json file2.json).
• Merge results into one table by default or provide an option for separate tables.
• Ensure error handling for invalid files or URLs.