Envelopes now match up side to side
Changed letter addition animation
Added new envelope swapping
Added a small rotation animation for being able to delete
Renamed functions
[UNSTABLE] Simplified rearrangement check as part of rearrangement overhaul
[UNSTABLE] Improved stabilization of new letter swapping
Fixed multiple placeholder slot bug
Fixed small animation issue
Added some asserts and made some simall changes
Stabilized letter rearrangement (intermittent bugs on rapid shifting)