[Version 3.1.1] Ability to link props with a specific bone

Version3.1.1

↓I added below feature

• Switch between Orthographic and Projective
• Linking Props and Bones
• Upload artwork to VroidHub

Next update schedule is here
https://evelyngamedev.notion.site/5bb7e50c57564d66ba72eca8aa9dc6f9?v=3e6aac0ab4ce4394bea23f903a937fe0

I'll continue to update for users.