feat!: add jsxImportSource; Vue 3.3+ is required

BREAKING CHANGE: drop support for Vue 3.2 and below

See https://blog.vuejs.org/posts/vue-3-3#jsx-import-source-support

It doesn't need to be explicitly set for most projects because Volar /
vue-tsc would detect the Vue version and set it automatically.

But in a pure TS/TSX project, it's required to set it manually. So we
are explicitly adding it here.

tsconfig.json

@@ -19,6 +19,7 @@
 
     // Required in Vue projects
     "jsx": "preserve",
+    "jsxImportSource": "vue",
 
     // `"noImplicitThis": true` is part of `strict`
     // Added again here in case some users decide to disable `strict`.