Add TurboPack details to README and update Next.js config

The README.md was updated with information about TurboPack which is now used by default and still experimental. The Next.js configuration was also modified to support this. Instructions on how to switch back to the default bundler in case of any issues were added as well.

apps/web/next.config.mjs

@@ -26,7 +26,6 @@ const config = {
   reactStrictMode: true,
   /** Enables hot reloading for local packages without a build step */
   transpilePackages: INTERNAL_PACKAGES,
-  pageExtensions: ['ts', 'tsx'],
   images: {
     remotePatterns: getRemotePatterns(),
   },
@@ -34,6 +33,9 @@ const config = {
     mdxRs: true,
     taint: true,
     instrumentationHook: true,
+    turbo: {
+      resolveExtensions: ['.ts', '.tsx', '.js', '.jsx'],
+    },
     optimizePackageImports: [
       'recharts',
       'lucide-react',