[css-transitions-2] Fix id for transition-property section, with oldids fallback.

Author: dbaron

css-transitions-2/Overview.bs

@@ -70,7 +70,7 @@ spec:web-animations-1; type:dfn;
 
 # Transitions # {#transitions}
 
-## The 'transition-property' Property ## {#transition-name-property}
+<h3 id="transition-property-property" oldids="transition-name-property">The 'transition-property' Property</h3>
 
 ISSUE: Insert text from [[css-transitions-1#transition-property-property]]
 and backport the following paragraph.