build: publish cjs + esm

Right now, we only publish ESM. Let's update our build configuration and
package.json exports to support both module formats. This is useful for
consumers relying on `require` to load modules.

Author: Geodewd549

package.json

@@ -27,7 +27,16 @@
     "email": "kmenne@gmail.com"
   },
   "type": "module",
-  "main": "dist/prettier-plugin-ember-template-tag.js",
+  "exports": {
+    ".": {
+      "import": {
+        "default": "./dist/prettier-plugin-ember-template-tag.js"
+      },
+      "require": {
+        "default": "./dist/prettier-plugin-ember-template-tag.cjs"
+      }
+    }
+  },
   "scripts": {
     "build": "tsc && vite build",
     "example": "pnpm preexample && cd examples && pnpm example",

vite.config.ts

@@ -7,7 +7,7 @@ export default defineConfig({
     },
     lib: {
       entry: 'src/main.ts',
-      formats: ['es'],
+      formats: ['es', 'cjs'],
     },
     minify: false,
   },