add notes about nextjs 13.x unsupported features

README.md

@@ -65,6 +65,8 @@ module.exports = withAxiom({
 
 ### Web Vitals
 
+:warning: Web-Vitals aren't supported yet in Next.js 13 and above. Please use Next.js 12 or below.
+
 Go to `pages/_app.js` or `pages/_app.ts` and add the following line to report web vitals:
 
 ```js
@@ -76,6 +78,8 @@ export { reportWebVitals } from 'next-axiom';
 Wrapping your handlers in `withAxiom` will make `req.log` available and log
 exceptions:
 
+:warning: Nextjs 13.x server side components are not yet supported.
+
 ```ts
 import { withAxiom, AxiomAPIRequest } from 'next-axiom';