Build fallback bundles for old browsers

This feature adds a lot of dependencies and some build time, but many
large screens at venues are powered by outdated android boxes and won't
be able to display anything otherwise. Modern browsers are not affected,
the fallback bundles are only downloaded by browsers that actually need
them.

package.json

@@ -27,6 +27,7 @@
   "devDependencies": {
     "@tsconfig/node18": "^2.0.1",
     "@types/node": "^18.16.17",
+    "@vitejs/plugin-legacy": "^4.1.0",
     "@vitejs/plugin-vue": "^4.2.3",
     "@vue/tsconfig": "^0.4.0",
     "git-describe": "^4.1.1",

vite.config.ts

@@ -4,6 +4,7 @@ import { defineConfig } from 'vite'
 import vue from '@vitejs/plugin-vue'
 import viteCompression from 'vite-plugin-compression';
 import { gitDescribeSync } from 'git-describe';
+import viteLegacy from '@vitejs/plugin-legacy'
 
 var version;
 
@@ -23,7 +24,9 @@ export default defineConfig({
     __VERSION__: JSON.stringify(version)
   },
   plugins: [
-    vue(), viteCompression()
+    vue(),
+    viteCompression(),
+    viteLegacy(),
   ],
   resolve: {
     alias: {