[Feature]: Add CLI

[321BadgerCode]

Feature Summary

A command line interface to access the API and run commands like "uniconvert image.jpg -o image.png"

Why is this feature needed?

Note

Going to need a manual with like cli.1, so users can man uniconverter

Example command

uniconvert input.jpg -o output.png
uniconvert input1.jpg,input2.pdf -o output.png

Required arg: input file(s)

Optional args

• output filename (default: input filename + new extension)
• tools (example: compression, resizing, etc.): probably best to have own parser for this like inline CSS code in HTML, so that this arg can also be a script file and can have multiple commands like resizing and compression in 1