• fix: #2552 DOM init doesn't sizeToContent
• fix: #2561 issues with sizeToContent animation, cleanup, etc...
• fix: #2427 sizeToContent supports rem/em cell height
• fix: #2558 remove style node in shadow root
• fix: #2556 make sure 'new GridStack(el)' set el.gridstack=this right away
• cleanup: #2550 Optimize resize arrow (~88% lighter from 1.82 KB to 225B)