[css-highlights-api] Avoid use of RFC2119 keywords in non-normative text

Author: frivoal

css-highlight-api-1/Overview.bs

@@ -229,16 +229,16 @@ Registering Custom Highlights</h3>
 		The <dfn>custom highlight name</dfn> assigned to a [=custom highlight=] when it is [=registered=]
 		is used to identify the highlight during styling (see [[#styling-highlights]]).
 
-	Note: When registering a [=custom highlight=], authors are recommended to use a
+	Note: When registering a [=custom highlight=], authors are advised to use a
 	[=custom highlight name=] that is a valid CSS [=identifier=]. Using a name that is not a valid
 	identifier can make the highlight hard, and in some cases impossible, to style via CSS.
 
 	Note: It is possible to [=register=] a [=custom highlight=] with more than one [=custom highlight name=].
 	However, using more than one name to style a highlight will assign the highlight multiple different sets
 	of styles, without a way to control the stacking order of conflicting styles within these sets
-	during [[#painting|painting]]. This may be limiting for authors and may cause confusing painting behavior
+	during [[#painting|painting]]. This could be limiting for authors and could cause confusing painting behavior
 	(see the <a href="#styling-problems-with-multiple-names-per-highlight">example</a> below for more context). Therefore,
-	<b>it is recommended that authors only use one name per highlight during styling</b>.
+	<b>authors are advised to only use one name per highlight during styling</b>.
 	<div class=example id=styling-problems-with-multiple-names-per-highlight>
 		<xmp highlight=html>
 			<style>
@@ -261,7 +261,7 @@ Registering Custom Highlights</h3>
 			</script>
 		</xmp>
 		In the example above, the same [=custom highlight=] object is [=registered=] under the names 'foo' and 'bar'.
-		Since each of the [=style rules=] target the same highlight and have the same [=specificity=], authors may
+		Since each of the [=style rules=] target the same highlight and have the same [=specificity=], authors might
 		expect the last rule to win in cascading order and the highlighted content to be green. However, each highlight
 		name gets an independent set of highlight styles, and the highlight will be painted once per name. In
 		this case, because 'foo' was registered before 'bar', the highlight will be first painted with 'foo''s