docs(readme): add production build testing section

Explains how to test production-only features like redirects
using yarn build and yarn serve, addressing confusion from PR

Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>
#38 where redirects only work in production builds.

Author: mnencia

README.md

@@ -63,6 +63,20 @@ yarn build
 This command generates static content into the `build` directory and can be
 served using any static contents hosting service.
 
+## Testing Production Features
+
+Some features, like redirects, only work in production builds and are not
+available during local development (`yarn start`). To test these features
+locally:
+
+```bash
+yarn build
+yarn serve
+```
+
+This builds the site and serves it locally, allowing you to test production-only
+features.
+
 ## Deployment
 
 Using SSH: