[mediaqueries-3] Mention ASCII case-insensitivity, not only case-insensitivity.

Author: emilio

mediaqueries-3/Overview.html

@@ -593,8 +593,9 @@ <h2 id=syntax><span class=secno>3. </span>Syntax</h2>
   <p><code>RESOLUTION</code> is to be added to the CSS2 <code>term</code>
    production.
 
-  <p>CSS style sheets are generally case-insensitive, and this is also the
-   case for media queries.
+ <p>CSS style sheets are generally <a
+   href="https://infra.spec.whatwg.org/#ascii-case-insensitive">ASCII
+   case-insensitive</a>, and this is also the case for media queries.
 
   <p>In addition to conforming to the syntax, each media query needs to use
    media types and media features according to their respective specification

mediaqueries-3/Overview.src.html

@@ -432,8 +432,9 @@ <h2>Syntax</h2>
 <p><code>RESOLUTION</code> is to be added to the CSS2
 <code>term</code> production.</p>
 
-<p>CSS style sheets are generally case-insensitive, and this is
-also the case for media queries.</p>
+<p>CSS style sheets are generally <a
+href="https://infra.spec.whatwg.org/#ascii-case-insensitive">ASCII
+case-insensitive</a>, and this is also the case for media queries.</p>
 
 <p>In addition to conforming to the syntax, each media query needs to use
 media types and media features according to their respective specification