add filename

docs/platforms/javascript/common/configuration/integrations/vue.mdx

@@ -22,7 +22,7 @@ Adds error and span instrumentation for Vue applications.
 If the Vue application is not defined from the start, you can add error monitoring for Vue-specific errors later on.
 To manually add the integration for late-defined Vue applications:
 
-```javascript
+```javascript {filename:main.js}
 import * as Sentry from '@sentry/vue';
 
 Sentry.init({