fix: add lemonade theme

Author: remadex

doc-app/app/components/theme-selector.gts

@@ -5,7 +5,7 @@ import { fn } from '@ember/helper';
 import { on } from '@ember/modifier';
 import type Owner from '@ember/owner';
 
-const THEMES = ['nord', 'dracula', 'cupcake', 'corporate'] as const;
+const THEMES = ['nord', 'dracula', 'cupcake', 'corporate', 'lemonade'] as const;
 
 interface ThemeSelectorSignature {
   Args: {

doc-app/app/styles/app.css

@@ -8,7 +8,8 @@
     nord --default,
     dracula,
     cupcake,
-    corporate;
+    corporate,
+    lemonade;
 }
 @import '@triptyk/ember-input/dist/app.css';
 @import '@triptyk/ember-ui/dist/app.css';