[css-writing-modes] Fix for validator.w3.org/nu

Author: kojiishi

css-writing-modes/Overview.bs

@@ -1278,7 +1278,7 @@ Orienting Text: the 'text-orientation' property</h3>
   <p class="note">Changing the value of this property may affect inline-level alignment.
     Refer to <a href="#text-baselines">Text Baselines</a> for more details.</p>
 
-  UAs may accept <dfn type=value for=text-orientation>sideways-right</dfn>
+  UAs may accept <dfn dfn-type=value dfn-for=text-orientation>sideways-right</dfn>
   as a value that computes to ''sideways''
   if needed for backward compatibility reasons.
 
@@ -1696,7 +1696,7 @@ Abstract-to-Physical Mappings</h3>
   <table class="complex data">
     <caption>Abstract-Physical Mapping</caption>
     <colgroup class="header"></colgroup>
-    <colgroup span=10></colgroup>
+    <colgroup span=8></colgroup>
     <thead>
       <tr>
         <th scope="row">'writing-mode'</th>