Instructions for Creating a GitHub App Incorrect

### Describe the bug The documentation here... https://github.com/github-community-projects/private-mirrors/blob/main/docs/developing.md#github-app ...notes that you should set your **Webhook URL** to... http://localhost:3000/api/webhooks ...however, when I try to do that, I get the following error... Webhook URL is not supported because it isn't reachable over the public Internet (localhost) ### To Reproduce 1. Follow the instructions on this page: - https://github.com/github-community-projects/private-mirrors/blob/main/docs/developing.md#github-app 2. When you try to save the webhook, you receive a notice that the webhook must be reachable over the public Internet. 3. You cannot save the webhook, so you cannot move on with local development. ### Expected behavior 1. Follow the instructions on this page: - https://github.com/github-community-projects/private-mirrors/blob/main/docs/developing.md#github-app 2. When you try to save the webhook, you are able to save successfully. 3. You are able to continue with local development. ### Screenshots Here is a screenshot of the error: <img width="353" height="204" alt="Image" src="https://github.com/user-attachments/assets/d8cc648c-d00c-4412-8fc4-1780a3e72572" /> ### Additional context Though this error makes sense to me, it leaves me wondering if these instructions ever worked. It would be good if the instructions suggest the best way to work around this issue.