Justify nav’s content to the end

This is to bring back the old behaviour when header was a flex with
space-between, that pushed the menu as far to the right as possible.

web/static/public.css

@@ -275,6 +275,7 @@ nav ul, .campsite_type_features ul {
 nav ul {
     flex-wrap: wrap;
     align-items: center;
+    justify-content: end;
 }
 
 nav a, nav button, label[for="menuShowHide"] {