mkRedundantOption: use multi-line string with html

flake.nix

@@ -55,7 +55,19 @@
 
     mkRedundantOption = name: value: attrs: lib.mkOption {
       inherit (attrs) type default;
-      description = "${attrs.description}\n\n\<div class=admonition-warning>\<p class=admonition-title>Redundant\</p>\<p>${mkRedundantOptionDescription name value}\</p>\</div>";
+      description = ''
+        ${attrs.description}
+        
+        
+        <div class=admonition-warning>
+          <p class=admonition-title>
+            Redundant
+          </p>
+          <p>
+            ${mkRedundantOptionDescription name value}
+          </p>
+        </div>
+      '';
     };
   };
 }