Different Double Slabs

This release is tested with all versions 1.13 and up!*

*The only caveat is that the resource pack won't automatically have support for any new slabs added after 1.21.0, so message me on Discord reminding me to add them! (@owehttamy)

Changes:

• Added a new modding support tutorial video

It's never been easier to add support for mods!

• Added new modding support template files
• Fixed bamboo_thatch slab missing thatch ends
• Improved models for Nature's Spirit's thatch slabs