1.6.0 preview 1: new mini-game, import/export, and UI improvements

The preview version was updated to 1.6.0-preview.1.

The main changes are: a new mini-game and respective task (3 tasks for now), import/export, and various UI improvements.

The full change log is available in the preview version' description.

As usual, please let me know if you find any issues or inconsistencies in this version.

There will be later a second preview with a new ending and the ability to open/review endings that were already explored, and that would be it for the 1.6.0 version.