The Atlas Logger is used to create the atlas files in your resource packs after the 1.19.3 update broke them.
Put the Python script into the .minecraft/resourcepacks folder and run it. Choose between the Singles or Folders option to determine how the script will generate the atlas file. Then enter in the name of the resource pack and it will create the file for you inside of your resource pack.
Thanks to WingedSeal for suggesting several code refactors which cleaned up this and many other scripts.