[css-counter-styles-3][editorial] Make it slightly clearer that 'speak-as' isn't just for speech synthesizers. w3c#6040

Author: tabatkins

css-counter-styles-3/Overview.bs

@@ -1112,8 +1112,8 @@ Speech Synthesis: the '@counter-style/speak-as' descriptor</h3>
 	</pre>
 
 	A counter style can be constructed with a meaning that is obvious visually,
-	but impossible to meaningfully represent via a speech synthesizer,
-	or possible but nonsensical when naively read out.
+	but impossible to meaningfully represent via a speech synthesizer or other non-visual means,
+	or possible but nonsensical when naively transformed.
 	The '@counter-style/speak-as' descriptor describes how to synthesize the spoken form of a counter formatted with the given counter style.
 	Values have the following meanings:
 
@@ -1164,6 +1164,9 @@ Speech Synthesis: the '@counter-style/speak-as' descriptor</h3>
 			for the counter styles participating in the loop.
 	</dl>
 
+	Note: The values above are defined by referring to "speaking" a value,
+	but should be understand as referring to any non-visual means of representing text.
+
 	<div class='example'>
 		The ability to defer pronunciation to another counter style can help when the symbols being used aren't actually letters.
 		For example, here's a possible definition of a ''circled-lower-latin'' counter-style, using some special Unicode characters: