Notably a new scrollbar and a couple necessary class fixes. View details for more info.

[frontend]
Added GSAP for animations (incomplete and buggy)
Added custom scrollbar and TS definition
Added ErrorHandler class (WIP)
Applied custom scrollbar to main content
Window borders now use subtler color
Normalized all role attributes
Fixed CharCount class to properly adjust to window resize
Fixed PanelNav class improperly handling 404 pages