docs: fix 'browser to server' build config (libp2p#66)

Co-authored-by: chengcheng <[email protected]>

Author: eng-cc

examples/browser-to-server/vite.config.js

@@ -1,9 +1,9 @@
 export default {
   build: {
-    target: 'es2020'
+    target: 'es2022'
   },
   optimizeDeps: {
-    esbuildOptions: { target: 'es2020', supported: { bigint: true } }
+    esbuildOptions: { target: 'es2022', supported: { bigint: true } }
   },
   server: {
     open: true