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Merge pull request #139 from SneakyTactician/imgbot

[ImgBot] Optimize images

Merge pull request #138 from SneakyTactician/Dungeons

Updated thee C# version to fix a CI build error.

Pre D* Algorithm

Added a placeholder staircase up and staircase down texture.

Added the missing texture texture.

Working up to structures.

Code quality improvements.