build: Update web output filenames

Author: qdot

js/vite.config.ts

@@ -1,4 +1,3 @@
-// vite.config.js
 import { resolve } from 'path';
 import { defineConfig } from 'vite';
 import dts from 'vite-plugin-dts';
@@ -10,7 +9,12 @@ export default defineConfig({
       entry: resolve(__dirname, 'src/index.ts'),
       name: 'buttplug',
       // the proper extensions will be added
-      fileName: 'buttplug',
+      fileName: (format): string => {
+        if (format === 'umd') {
+          return 'buttplug.js';
+        }
+        return 'buttplug.mjs';
+      },
     },
     outDir: 'dist/web',
   },