Add Vue JSX options example

packages/integrations/vue/README.md

@@ -98,6 +98,7 @@ export default {
 ### jsx
 
 You can use Vue JSX by setting `jsx: true`.
+
 __`astro.config.mjs`__
 
 ```js
@@ -112,3 +113,21 @@ export default defineConfig({
 ```
 
 This will enable rendering for both Vue and Vue JSX components. To customize the Vue JSX compiler, pass an options object instead of a boolean. See the `@vitejs/plugin-vue-jsx` [docs](https://github.com/vitejs/vite/tree/main/packages/plugin-vue-jsx) for more details.
+
+__`astro.config.mjs`__
+
+```js
+import { defineConfig } from 'astro/config';
+import vue from '@astrojs/vue';
+
+export default defineConfig({
+  integrations: [
+    vue({
+      jsx: {
+        // treat any tag that starts with ion- as custom elements
+        isCustomElement: tag => tag.startsWith('ion-')
+      }
+    })
+  ],
+});
+```