Create ThemeSwitcher btn

src/components/ui/themeSwitcher/ThemeSwitcher.jsx

@@ -0,0 +1,19 @@
+import Button from "../button/button.jsx";
+import React from "react";
+
+export default function ThemeSwitcher() {
+
+    const switchTheme = () => {
+
+        const currentTheme = localStorage.getItem("theme");
+        let newTheme = currentTheme === "light" ? "dark" : "light";
+
+        if(currentTheme === null) newTheme = "dark";
+
+        localStorage.setItem("theme", newTheme);
+
+        window.dispatchEvent(new Event("theme-changed"));
+    };
+
+    return <Button variant={"default"} onClick={switchTheme}> Changer de thème </Button>
+}