Add animate-shimmer class

[chirag04]

Currently tailwind has animate-pulse which is great in itself but it can be bit overwhelming at time specially on grids/lists. Shimmer is a popular animation pattern for placeholders on a grid or list view. If tailwind can support that out-of-box that would be awesome!

[PeerRich]

this could be a great native class: https://twitter.com/delba_oliveira/status/1549426693357568001?s=12&t=Y7fP0FaYs5SfKQx2eEjhrg

[aryomuzakki]

this seems to be very old discussion, too bad no animate-shimmer added to v4

here is my version which make it reusable individual skeleton and adopting to v4, from the twitter post
https://play.tailwindcss.com/TvcbZjU6W5

maybe one day this will be updated to use pseudo element