[css-align] align-self actually describes the normal values for itself anyway.

Author: tabatkins

css-align/Overview.bs

@@ -804,7 +804,6 @@ Block/Cross-Axis Alignment: the 'align-self' property</h3>
 
 	The <dfn value for="align-self">normal</dfn> keyword
 	represents the "default" alignment for the layout mode.
-	Its behavior depends on the layout model, as described for 'justify-self'.
 
 	The ''align-self/stretch'' keyword is as defined in [[#justify-self-property]].