[css-values][meta] Fix example, per w3c#4101.

Author: tabatkins

css-values-4/Overview.bs

@@ -2676,8 +2676,8 @@ Argument Ranges</h4>
 	(because the JS function's input is in radians,
 	and one cannot perfectly express a value of π/2 in JS numbers),
 	is defined so that roundtripping of values works;
-	''tan(atan(1/0))'' yields +∞,
-	''tan(atan(-1/0))'' yields -∞,
+	''tan(atan(1 / 0))'' yields +∞,
+	''tan(atan(-1 / 0))'' yields -∞,
 	''atan(tan(90deg))'' yields ''90deg'',
 	and ''atan(tan(-90deg))'' yields ''-90deg''.