[css-scroll-snap] Remove stray point value.

Author: fantasai

css-scroll-snap/Overview.bs

@@ -243,7 +243,7 @@ Scroll Snapping Rules: the 'scroll-snap-type' property {#scroll-snap-type}
 
     <pre class="propdef">
     Name: scroll-snap-type
-    Value: none | [ x | y | block | inline | both ] [ mandatory | proximity ]? ]! | point
+    Value: none | [ x | y | block | inline | both ] [ mandatory | proximity ]?
     Initial: none
     Applies to: all elements
     Inherited: no