[css-display] Use HTML definition of “submittable element” since that's much better than this unweildy desription. #1024 #540

Author: fantasai

css-display/Overview.bs

@@ -484,9 +484,7 @@ Box Generation: the ''display/none'' and ''display/contents'' keywords</h3>
 
 			This value is treated as ''display: none'' on replaced elements,
 			form controls
-			(i.e. user interface elements whose element type
-			can accept and/or submit user data,
-			such as <code>&lt;input&gt;</code> and <code>&lt;button&gt;</code>),
+			(such as <a href="https://html.spec.whatwg.org/multipage/forms.html#category-submit">submittable elements</a> in [[HTML]]),
 			and (obviously) empty elements.
 			The effect is exactly as if the UA style sheet had specified
 			''display: none !important'' on such elements,