Armory Preview Cache - v22.1

• Documentation-only release: the mod is identical to v22 (same compiled resource).
• Rewrites the install notes packaged with the mod and the README status: one current status line instead of the compatibility-candidate and test-build notes left from the game-build update. Caching works in live play; a category's thumbnails are kept once every preview in it has rendered.
• Lists one loader requirement, Bingus Shared Loader v18.