docs: add tip on browser extensions to perf guide

docs/guide/performance.md

@@ -6,6 +6,10 @@ While Vite is fast by default, performance issues can creep in as the project's
 - Slow page loads
 - Slow builds
 
+## Avoid Browser Extensions
+
+Some browser extensions may interfere with requests and slow down startup and reload times for large apps, especially when using browser dev tools. We recommend creating a dev-only profile without extensions while using Vite's dev server in these cases. Another option is using Incognito mode, that should also provide an extra speed up when loading your app.
+
 ## Audit Configured Vite Plugins
 
 Vite's internal and official plugins are optimized to do the least amount of work possible while providing compatibility with the broader ecosystem. For example, code transformations use regex in dev, but do a complete parse in build to ensure correctness.