Greyscale

• Update to include 1.21.10 textures

Because of changes to Resource Packs in 1.21.5, this update is only for 1.21.5 and later. Older versions can still use older releases.

• Update the pack version to 13 for 1.19.4
• Add 1.19.4 textures

Note: this will have a red warning on older versions, but the pack will still work, so it can be ignored.