init wompum header image

layouts/partials/css-variables.html

@@ -0,0 +1,9 @@
+<style>
+    :root {
+        {{ range $colorName, $shades := site.Data.colors }}
+            {{ range $shade, $value := $shades }}
+                --{{ $colorName }}-{{ $shade }}: {{ $value }};
+            {{ end }}
+        {{ end }}
+    }
+</style>