Improve placeholder foreground in dark theme

Author: annalifatou

themes/MinimalWave-dark-floral-color-theme.json

@@ -178,7 +178,7 @@
 		"input.foreground": "#ffffff",
 		"input.background": "#6666cb48",
 		"input.border": "#141415",
-		"input.placeholderForeground": "#3e3e71",
+		"input.placeholderForeground": "#7171b3",
 		"inputOption.activeBorder": "#ffffff",
 		"inputOption.activeForeground": "#ffffff",