Update packages/cloudflare/README.md

Co-authored-by: Pete Bacon Darwin <pbacondarwin@cloudflare.com>

Author: vicb

packages/cloudflare/README.md

@@ -66,7 +66,7 @@ const config: OpenNextConfig = {
 export default config;
 ```
 
-## Know issues
+## Known issues
 
 - Next cache is not supported in the experimental branch yet
 - `▲ [WARNING] Suspicious assignment to defined constant "process.env.NODE_ENV" [assign-to-define]` can safely be ignored