Add web-animations.vim

See also: http://www.w3.org/TR/web-animations/

test/test.html

@@ -736,6 +736,11 @@
 }
 </style>
 <style>
+.web-animations {
+  display: auto;
+}
+</style>
+<style>
 .will-change {
   will-change: scroll-position;
 }