[css-align] Add readability issue. Need to wordsmith later.

Author: fantasai

css-align/Overview.bs

@@ -547,6 +547,8 @@ Baseline Content-Alignment</h3>
 	See [[#align-by-baseline]].
 	This increases the intrinsic size of the box.
 
+	ISSUE: Make that last paragraph more readable.
+
 <h3 id="overflow-scroll-position">
 Overflow and Scroll Positions</h3>