feat: animations, responsive design

Animations
- added opacity animation for experience page
- added stagger animation for navbar items on mobile
- added animation for landing page for years and language indications

Pages
- About Page mockup

Redesign
- Navbar to include icons on desktop

components/notfound_templ.txt

@@ -0,0 +1 @@
+<main class=\"w-full h-full flex flex-col gap-0 items-center justify-center\"><h1 class=\"text-3xl\">404</h1><p class=\"text-base\">Page not found</p></main>