docs: update semi-animation-styled readme, add link of animate.css

packages/semi-animation-styled/README.md

@@ -1,6 +1,6 @@
 > Stylesheet for animation
 
-- Provides rich transition effects based on `animate.css`
+- Provides rich transition effects based on `animate.css` (https://github.com/animate-css/animate.css)
 - It is easy to use. Building rich and vivid front-end pages through adding various atomic animation style to elements
 
 ## Usage