Add additional any-* consideration note to pointer/hover

The rationale given in any-pointer/any-hover about not relying
exclusively on any-* is equally valid in reverse here. This does not
imply that authors must design for "lowest common denominator", but
simply opens up the possibility that they may wish to keep non-primary
inputs in mind when deciding on their layout/functionality.

mediaqueries/Overview.bs

@@ -1646,6 +1646,10 @@ Pointing Device Quality: the 'pointer' feature</h3>
 	even on devices whose pointing device can be described as ''fine'',
 	the UA may give a value of ''coarse'' or ''pointer/none'' to this media query,
 	to indicate that the user has difficulties manipulating the pointing device accurately or at all.
+	In addition, even if the primary input mechanism has ''fine'' pointing accuracy,
+	there may be additional ''coarse'' input mechanisms available to the user. Authors may
+	wish to query the 'any-pointer' media feature to take these other ''coarse'' potential
+	input mechanisms into account.
 
 	<div class="example">
 		<pre>
@@ -1709,6 +1713,8 @@ Hover Capability: the 'hover' feature</h3>
 	For accessibility reasons, even on devices that do support hovering,
 	the UA may give a value of ''hover: none'' to this media query,
 	to opt into layouts that work well without hovering.
+	Note that even if the primary input mechanism has 'hover: hover' capability,
+	there may be additional input mechanisms available to the user that do not provide hover capabilities.
 
 	<div class="example">
 		<pre>