feat: add initial styling and layout for portal views

- Created a global CSS file for consistent styling across the application.
- Implemented the Explore, Home, Topics, and various user views with responsive design.
- Added a Login view with OTP functionality and a Checkout view for order processing.
- Developed a NotFound view for handling 404 errors.
- Established a configuration file for Vite with Tailwind CSS integration.

frontend/portal/src/main.js

@@ -0,0 +1,26 @@
+import { createApp } from 'vue';
+import { createPinia } from 'pinia';
+import PrimeVue from 'primevue/config';
+import Aura from '@primevue/themes/aura';
+import App from './App.vue';
+import router from './router';
+
+import './assets/main.css';
+import 'primeicons/primeicons.css';
+
+const app = createApp(App);
+
+app.use(createPinia());
+app.use(router);
+app.use(PrimeVue, {
+    theme: {
+        preset: Aura,
+        options: {
+            prefix: 'p',
+            darkModeSelector: '.my-app-dark',
+            cssLayer: false
+        }
+    }
+});
+
+app.mount('#app');