[css-text] fix bikeshed error in propdef tab-size, animation type value

Author: arronei

css-text/Overview.bs

@@ -721,8 +721,7 @@ Languages and Typesetting</h4>
     Applies to: block containers
     Inherited: yes
     Computed value: the specified integer or length made absolute
-    Animation type: <a href="http://www.w3.org/TR/css-transitions-1/#animtype-length">length</a>,
-    <a href="http://www.w3.org/TR/css-transitions-1/#animtype-number">number</a>, or calc
+    Animation type: <a href="http://www.w3.org/TR/css-transitions-1/#animtype-length">length</a>, <a href="http://www.w3.org/TR/css-transitions-1/#animtype-number">number</a>, or calc
     Canonical order: n/a
     </pre>