Tweak the editor help comment color for better readability

(cherry picked from commit 99bfaa6c6096c6ad25d13a3ecb447bb451f88892)

editor/editor_help.cpp

@@ -50,7 +50,7 @@ void EditorHelp::_init_colors() {
 	text_color = get_color("default_color", "RichTextLabel");
 	headline_color = get_color("headline_color", "EditorHelp");
 	base_type_color = title_color.linear_interpolate(text_color, 0.5);
-	comment_color = text_color * Color(1, 1, 1, 0.4);
+	comment_color = text_color * Color(1, 1, 1, 0.6);
 	symbol_color = comment_color;
 	value_color = text_color * Color(1, 1, 1, 0.6);
 	qualifier_color = text_color * Color(1, 1, 1, 0.8);