refactor: upgrade project setup (#646)

vitest.config.ts

@@ -0,0 +1,22 @@
+import { defineConfig } from 'vitest/config';
+import { babel } from '@rollup/plugin-babel';
+import Jsx from './packages/babel-plugin-jsx/src';
+
+export default defineConfig({
+  plugins: [
+    babel({
+      babelHelpers: 'bundled',
+      extensions: ['.tsx', '.jsx'],
+      plugins: [
+        [
+          Jsx,
+          { optimize: true, isCustomElement: (tag: string) => /^x-/.test(tag) },
+        ],
+      ],
+    }),
+  ],
+  test: {
+    globals: true,
+    environment: 'jsdom',
+  },
+});