[css-display-3][css-display-4] Export 'invisible box' as a term

Author: fantasai

css-display-3/Overview.bs

@@ -1182,11 +1182,13 @@ Invisibility: the 'visibility' property</h2>
 		<dt><dfn>visible</dfn>
 		<dd>
 			The generated box is visible, as normal.
+
 		<dt><dfn>hidden</dfn>
 		<dd>
 			Any boxes generated by the element are [=invisible=].
 			Descendants of the element can, however, be visible
 			if they have ''visibility: visible''.
+
 		<dt><dfn>collapse</dfn>
 		<dd>
 			Indicates that the box is <dfn dfn for noexport>collapsed</dfn>,
@@ -1210,7 +1212,7 @@ Invisibility: the 'visibility' property</h2>
 	Authors should avoid creating these situations
 	until the tooling situation improves.
 
-	<dfn>Invisible</dfn> boxes are not rendered
+	<dfn export lt="invisible box" local-lt="invisible">Invisible boxes</dfn> are not rendered
 	(as if they were fully transparent),
 	cannot be interacted with
 	(and behave as if they had ''pointer-events: none''),

css-display-4/Overview.bs

@@ -1523,7 +1523,7 @@ Invisibility: the 'visibility' property</h2>
 	Authors should avoid creating these situations
 	until the tooling situation improves.
 
-	<dfn>Invisible</dfn> boxes are not rendered
+	<dfn export lt="invisible box" local-lt="invisible">Invisible boxes</dfn> are not rendered
 	(as if they were fully transparent),
 	cannot be interacted with
 	(and behave as if they had ''pointer-events: none''),