build: remove single-file inlining

Compile JavaScript code as an IIFE, allowing us to avoid needing to
inline anything.

This makes the code about 10% faster for me
(tests run in 105s instead of 120s), and the size on the bundle went
from 4MiB to 3.5MiB.

Additionally, I think I've finally figured out the issue that was
sometimes causing the FontAwesome icons to load incorrectly: sometimes
Puppeteer was parsing the CSS FontAwesome as Latin-1 instead of UTF-8!
Explicility setting the script to have `charset="utf-8"` seems to fix
this!

package.json

@@ -47,8 +47,6 @@
     "standard": "^17.0.0",
     "typescript": "^5.0.1-rc",
     "vite": "^4.0.3",
-    "vite-plugin-singlefile": "^0.13.1",
-    "vite-svg-loader": "^5.1.0",
     "yarn-upgrade-all": "^0.7.0"
   },
   "files": [

vite.config.ts

@@ -1,12 +1,28 @@
 import { defineConfig } from "vite"
-import { viteSingleFile } from "vite-plugin-singlefile"
-import svgLoader from 'vite-svg-loader'
 
 export default defineConfig({
+  base: './',
   plugins: [
-    // bundle everything into a single `index.html`
-    viteSingleFile(),
-    // unsure if this is working properly for fontawesome fonts
-    svgLoader(),
-  ],
-})
+    {
+      name: 'IIFE-converter',
+      config(currentConfig, _unused) {
+        return {
+          ...currentConfig,
+          build: {
+            ...currentConfig.build,
+            rollupOptions: {
+              ...currentConfig.build?.rollupOptions,
+              output: {
+                ...currentConfig.build?.rollupOptions?.output,
+                format: 'iife',
+              }
+            }
+          }
+        };
+      },
+      transformIndexHtml(html) {
+        return html.replace('<script type="module" crossorigin', '<script charset="utf-8"')
+      }
+    }
+  ]
+});