feat: add language switcher component and update layout

- Introduced a new LanguageSwitcher component to facilitate language switching in the application.
- Added an SVG icon for the language switcher button.
- Updated the Header component to adjust margin for better spacing.
- Modified the Navigation component's margin and top properties for improved layout.
- Adjusted the ThemeToggle button size for consistency with the new design.

src/layouts/Layout.astro

@@ -1,6 +1,7 @@
 ---
 import Footer from '@/components/Footer.astro'
 import Header from '@/components/Header.astro'
+import LanguageSwitcher from '@/components/LanguageSwitcher.astro'
 import Navigation from '@/components/Navigation.astro'
 import PhotoSwipe from '@/components/PhotoSwipe.astro'
 import Scrollbar from '@/components/Scrollbar.astro'
@@ -44,6 +45,7 @@ const fontStyle = `font-${themeConfig.global.font}`
 
     </div>
     <ThemeToggle />
+    <LanguageSwitcher />
     <Scrollbar />
     <PhotoSwipe />
   </body>