[css-grid-1] Tweak Changes list.

Author: fantasai

css-grid-1/Overview.bs

@@ -4545,7 +4545,7 @@ Clarifications</h4>
 				the <a>track sizing algorithm</a>’s calculations accordingly.</ins>
 			</blockquote>
 		<li id="change-2017-inner-outer">
-			Clarify inner vs. outer sizes in various instances.
+			Ensure that track sizes remain floored at zero during intrinsic sizing.
 			(<a href="https://github.com/w3c/csswg-drafts/issues/2655">Issue 2655</a>)
 	</ul>