chore: add homepage style

Author: OGALEXI

client/src/Components/TeacherHomepage/Homepage.tsx

@@ -15,7 +15,7 @@ const Homepage: React.FC = () => {
   return (
     <div>
       <Navbar />
-      <main className='flex flex-row justify-start w-full'>
+      <main className='flex flex-row justify-start w-full h-screen'>
         <Sidemenu />
         {selectedCourse ? <Outlet /> : <Instruction />}
       </main>