Thanks for the addendum!
By the way, I'm preparing an optimized version of this tileset for Godot. I'd be glad to get some advice when I publish it.
I used Adobe Photoshop to create this tileset. I used a different program just to check the animation.
The program is in Japanese, but here it is.
http://yaosame.m22.coreserver.jp/apps/autotile/