feat: Add themes marketplace page and components

src/lib/themes.ts

@@ -0,0 +1,25 @@
+
+export interface ZenTheme {
+  name: string
+  description: string
+  image: string
+  downloadUrl: string
+  id: string
+}
+
+export function getAllThemes(): ZenTheme[] {
+  // TODO: Fetch themes from the marketplace (database or JSON file)
+  return [
+    {
+      name: "Zen",
+      description: "The default theme for Zen Browser",
+      downloadUrl: "https://zen-browser.app/download", // idrc
+      id: "zen",
+      image: "https://imgs.search.brave.com/qcDBMGuBLvJGLxWR3IkZyg35vROTSZ2omLn_0iLU2rs/rs:fit:860:0:0:0/g:ce/aHR0cHM6Ly9pLnBp/bmltZy5jb20vb3Jp/Z2luYWxzLzgxL2Mz/LzE0LzgxYzMxNDI5/MmViOGM3YzYxNmY5/ZjM3YTRmZDI5ODU4/LmpwZw",
+    },
+  ];
+}
+
+export function getThemesFromSearch(themes: ZenTheme[], query: string): ZenTheme[] {
+  return themes.filter((theme) => theme.name.toLowerCase().includes(query.toLowerCase()));
+}