Add "Sliding Squares" Spinner as a Loading Animation

[AyendiSimeon1]

Description: I would like to propose adding a new loading spinner called "Sliding Squares" to the repository. This spinner will feature a set of squares that slide in and out, creating an engaging visual effect for loading states.

[davidhu2000]

do you have a demo of what this looks like?

[AyendiSimeon1]

This is a link to the demo : https://codepen.io/tomad8/pen/VwaPOXR