Mayland: set proper configuration for main-nav font

mayland/sass/_config-child-theme-deep.scss

@@ -322,6 +322,7 @@ $config-header: (
 		// Fonts
 		"font": (
 			"family": map-deep-get($config-global, "font", "family", "primary"),
+			"family-css-variable": '--font-headings',
 			"size": map-deep-get($config-global, "font", "size", "sm"),
 			"weight": 400,
 			"line-height": 1,

mayland/style-rtl.css

@@ -2720,7 +2720,7 @@ body:not(.fse-enabled) .main-navigation a {
 
 .footer-navigation .footer-menu a {
 	font-family: Poppins, sans-serif;
-	font-family: var(--font-base, Poppins, sans-serif);
+	font-family: var(--font-headings, Poppins, sans-serif);
 	font-weight: 400;
 	padding: 8px;
 	color: currentColor;

mayland/style.css

@@ -2737,7 +2737,7 @@ body:not(.fse-enabled) .main-navigation a {
 
 .footer-navigation .footer-menu a {
 	font-family: Poppins, sans-serif;
-	font-family: var(--font-base, Poppins, sans-serif);
+	font-family: var(--font-headings, Poppins, sans-serif);
 	font-weight: 400;
 	padding: 8px;
 	color: currentColor;