update README

Author: rinej

README.md

@@ -182,7 +182,7 @@ variables referenced here get updated since your local `.env` file is ignored.
 - `E2E_TESTING` (optional) - This needs to be set to `true` when running the e2e tests for performance regression testing.
    This happens usually automatically, read [this](tests/e2e/README.md) for more information
 
-> If your changes to .env aren't having an effect, try `rm -rf .rnef`, then re-run `npm run ios` or `npm run android`
+> If your changes to .env aren't having an effect, try `rm -rf .rock`, then re-run `npm run ios` or `npm run android`
 
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