removed UESR nobody as it breaks permissions

fixed dockerfile label syntax

bumped version to 5.0.0-beta3

remove encoded images from memory to prevent exhaustion

fixed a typo in release link

Merge pull request k4yt3x#434 from k4yt3x/black

Formatted code with Black and updated README

added a none option for -tune to address k4yt3x#401

updated wordings and translations

updated GUI for the newest version of Anime4kCPP

moved upscaler optional parameters into function definition