feat: wire up clerk

+ Add convex provider with clerk
+ Add clerk provider
+ Add account page
+ Add login page
+ Add sign up page
+ Add clerk middleware
+ Add Navbar component

src/app/signup/[[...signup]]/page.tsx

@@ -0,0 +1,9 @@
+import { SignUp } from '@clerk/nextjs';
+
+export default function SignUpPage() {
+  return (
+    <main className='flex flex-col items-center'>
+      <SignUp />
+    </main>
+  );
+}