Allow access to the render route when in development mode

Looks good. Clean and logical.

Attaching a static patch from the PR.

@TheodorosPloumis You can simply download the patch file from them merge request in gitlab, see https://www.drupal.org/docs/develop/git/using-gitlab-to-contribute-to-dr... →

@hydra This is what I did. Just wanted a static patch because the one from the PR may not apply at some time.

I see! It would be much nicer to download the patch into your repository. drupal.org ist not a patch hosting platform for your project. You can use relative paths in your composer.json to apply patches. This is not only more performant four your project, but also reduces the traffic for the d.o. infrastructure :)