[css-align-3] Gloss in-flow/out-of-flow jargon

Author: cvrebert

css-align-3/Overview.bs

@@ -2252,8 +2252,8 @@ Determining the Baselines of a Box</h3>
 		<dt>block containers
 		<dd>
 			The first/last [=baseline set=] of a <a>block container</a>
-			is taken from the first/last in-flow line box in the block container
-			or the first/last in-flow block-level child in the block container
+			is taken from the first/last [=in-flow=] line box in the block container
+			or the first/last [=in-flow=] block-level child in the block container
 			that contributes a set of first/last baselines,
 			whichever comes first/last.
 			If there is no such line box or child,
@@ -2349,7 +2349,7 @@ Determining the Baselines of a Box</h3>
 			and ''vertical-rl'' if 'direction' is ''rtl''.
 
 	For the purposes of finding the baselines of a box,
-	it and all its in-flow descendants with a scrolling mechanism (see the 'overflow' property)
+	it and all its [=in-flow=] descendants with a scrolling mechanism (see the 'overflow' property)
 	must be considered as if scrolled to their initial scroll position.
 	Additionally,
 	if the position of a [=scroll container=]’s first/last baseline