Add issue wrt multicol intrinsic extents

Author: fantasai

css3-sizing/Overview.html

@@ -384,7 +384,10 @@ <h2 id=terms><span class=secno>2. </span> Terminology</h2>
    <dt><dfn id=min-content-extent>min-content extent</dfn>
 
    <dd> Equivalent to the <a href="#max-content-extent"><i>max-content
-    extent</i></a>.
+    extent</i></a>. <span class=issue>Or should this be the minimum between
+    allowed break points? It might make sense in multi-col contexts to have
+    min-content and max-content extents be different, even if they are the
+    same elsewhere.</span>
 
    <dt><dfn id=fit-content-extent>fit-content extent</dfn>
 

css3-sizing/Overview.src.html

@@ -220,6 +220,7 @@ <h2 id="terms">
 		<dt><dfn>min-content extent</dfn>
 		<dd>
 			Equivalent to the <i>max-content extent</i>.
+			<span class="issue">Or should this be the minimum between allowed break points? It might make sense in multi-col contexts to have min-content and max-content extents be different, even if they are the same elsewhere.</span>
 
 		<dt><dfn>fit-content extent</dfn>
 		<dd>