Vue migration: Create src/main.ts entry point

[exhuma]

Part of #19.\n\nCreate src/main.ts:\n\nts\nimport { createApp } from 'vue'\nimport { createPinia } from 'pinia'\nimport App from './App.vue'\n\nconst app = createApp(App)\napp.use(createPinia())\napp.mount('#app')\n\n\nThis is the Vite entry point referenced in vite.config.js.