[css-color-adjust-1] Tweak section title

Author: fantasai

css-color-adjust-1/Overview.bs

@@ -434,8 +434,8 @@ Opting Out of a Forced Color Scheme: the 'forced-color-adjust' property {#forced
 		svg|foreignObject { forced-color-adjust: auto; }
 	</pre>
 
-Performance-based Color Schemes: the 'color-adjust' property {#perf}
-===============================
+Performance-based Color Adjustments: the 'color-adjust' property {#perf}
+===================================
 
 	On most monitors,
 	the color choices that authors make have no significant difference