Put the new code in a new fit_to_frame() method inside CameraMovement.gd. The old code did not work properly for images with width larger than their height.
Pixelorama now requires at least Godot 3.1.2 or 3.2.x to work, because TranslationServer.get_loaded_locales() was not included in older versions. If you're using an older version of Godot, please update. Godot 3.2.1 is the currently recommended version, until 3.2.2 is out.
Also updated the list of the translators.
Made a new "src" folder that will contain the source code files, like all the GDScript and scene files. Please read this for more details: https://www.gdquest.com/docs/guidelines/best-practices/godot-gdscript/
It made no sense to keep scenes separate from their scripts. More file organizing will follow soon.