Version 0.3 release: better Godot export and 2x2 autotile template

Changelog:

- Created a Godot export dialog, moving towards adding new autotiles to existing Godot tilesets

- Added 2x2 Wang template when only corner neighbours are tested

- Added selection between 2x2 and 3x3min exports modes on exporting to Godot

- You can now reload input texture with F5 key

- Created a tutorial video

- Latest debug builds are now publicly available at itch.io https://aleksandrbazhin.itch.io/tilepipe-testing