Porting floor tile resprites

[willowzeta]

About the PR

Porting #1635 and #1663 from the original repo.

Done with permission from the original spriter:

Why / Balance

wizden tiles ugly.

Technical details

only texture changes

Requirements

• I have read and am following the Pull Request and Changelog Guidelines.
• I have added media to this PR or it does not require an in-game showcase.
• If I am porting something, I have done my best to respect the appropriate licenses associated with the presented changes.

License

MIT

Breaking changes

Changelog

🆑 Alecksohs

• tweak: Resprites flooring!

[github-actions]

RSI Diff Bot; head commit 94abad2 merging into a6111f9
This PR makes changes to 1 or more RSIs. Here is a summary of all changes:

Resources/Textures/Decals/Overlays/greyscale.rsi

State	Old	New	Status
checkerNESW			Modified
checkerNWSE			Modified
fulltile_overlay			Modified
halftile_overlay			Modified
halftile_overlay_180			Modified
halftile_overlay_270			Modified
halftile_overlay_90			Modified
mono			Modified
offset			Modified
quartertile_overlay			Modified
quartertile_overlay_180			Modified
quartertile_overlay_270			Modified
quartertile_overlay_90			Modified
threequartertile_overlay			Modified
threequartertile_overlay_180			Modified
threequartertile_overlay_270			Modified
threequartertile_overlay_90			Modified