PLTF-1599: replace create github app instructions with script

enterprise/quick-start.mdx

@@ -175,9 +175,9 @@
 done
 ```
 
 Expected: each hostname above resolves to your VM's public IP address.
 
 Test that a runtime wildcard hostname resolves:
 
 ```bash
 getent hosts "test.runtime.${BASE_DOMAIN}" || nslookup "test.runtime.${BASE_DOMAIN}"
@@ -212,7 +212,7 @@
 done
 ```
 
 Any HTTP response code other than `000` is acceptable for reachability checks
 (for example `200`, `301`, `302`, `401`, `403`, `405`).
 
 If any check fails, stop and resolve before continuing:
@@ -223,10 +223,10 @@
 
 | Requirement | Why It Exists |
 |------------|----------------|
 | `443/TCP` inbound | Primary HTTPS entrypoint for users and service hostnames |
 | `30000/TCP` inbound | Replicated/KOTS Admin Console for install and configuration |
 | `80/TCP` inbound | HTTP entrypoint used for ingress/redirect behavior |
 | `*.runtime.<domain>` DNS + cert SAN | Runtime sandboxes are addressed by dynamic runtime-specific hostnames |
 | `replicated.app`, `proxy.replicated.com` | Replicated control-plane/license/install paths |
 | `images.r9...`, `charts.r9...`, `updates.r9...`, `install.r9...` | Vendor distribution image/chart/update/install endpoints |
 | `traefik.github.io` | Embedded cluster ingress chart repository |
@@ -292,7 +292,7 @@
 ### 5. Upload TLS certificate (if not provided with the install command)
 
 If you did not provide certificates with the `install` command, select **"Upload your own"**,
 enter your base domain under **Hostname**, upload your private key and SSL certificate, then click **Continue**.
 
 ![Upload TLS certificate](./images/upload-tls-certificate.png)
 
@@ -317,7 +317,7 @@
 
 ### Domain Configuration
 
 - Select **"Derive hostnames from domain (recommended)"**
 - Enter your base domain (e.g., `openhands.example.com`)
 
 ### Certificate Configuration
@@ -337,80 +337,11 @@
 
 #### Create a GitHub App
 
-1. Go to [github.com/settings/apps](https://github.com/settings/apps) and click **New GitHub App**.
-
-2. Set a unique **GitHub App name** (e.g., `ACME Corp OpenHands`).
-
-3. Set the **Homepage URL** to `https://app.<YOUR_BASE_DOMAIN>`.
-
-4. Under **Identifying and authorizing users**:
-   - Set the **Callback URL** to:
-     ```
-     https://auth.app.<YOUR_BASE_DOMAIN>/realms/allhands/broker/github/endpoint
-     ```
-   - Check the box for **Request user authorization (OAuth) during installation**
-
-5. Under **Webhook**:
-   - Set the **Webhook URL** to:
-     ```
-     https://app.<YOUR_BASE_DOMAIN>/integration/github/events
-     ```
-   - Generate a webhook secret:
-     ```bash
-     export WEBHOOK_SECRET=$(openssl rand -base64 32 | tr -dc A-Za-z0-9 | head -c 32)
-     echo $WEBHOOK_SECRET
-     ```
-   - Paste the generated value into the **Secret** field
-
-   <Warning>
-     Save the webhook secret value -- you will need to enter it in the Admin Console configuration.
-   </Warning>
-
-6. Under **Permissions**, configure the following:
-
-   **Repository permissions:**
-
-   | Permission | Access |
-   |-----------|--------|
-   | Actions | Read and write |
-   | Commit statuses | Read and write |
-   | Contents | Read and write |
-   | Issues | Read and write |
-   | Pull requests | Read and write |
-   | Webhooks | Read and write |
-   | Workflows | Read and write |
-
-   **Organization permissions:**
-
-   | Permission | Access |
-   |-----------|--------|
-   | Events | Read-only |
-
-   **Account permissions:**
-
-   | Permission | Access |
-   |-----------|--------|
-   | Email addresses | Read-only |
-
-7. Click **Create GitHub App**.
-
-8. On the GitHub App page, under **Client secrets**, click **Generate a new client secret**.
-   Save this value.
-
-9. Under **Private keys**, click **Generate a private key**. The `.pem` file downloads
-   automatically -- note its location.
+Run our [script](https://github.com/All-Hands-AI/OpenHands-Cloud/tree/main/scripts/create_github_app) to create a GitHub App configured for your install.
 
 #### Map GitHub App values to Admin Console
 
-Go back to the Installer Admin Console in your browser and enter the following values:
-
-| GitHub App Value | Admin Console Field |
-|-----------------|-------------------|
-| Client ID (shown on app page) | GitHub OAuth Client ID |
-| Client secret (from step 8) | GitHub OAuth Client Secret |
-| App ID (shown on app page) | GitHub App ID |
-| Webhook secret (from step 5) | GitHub App Webhook Secret |
-| Private key file (from step 9) | GitHub App Private Key (file upload) |
+Go back to the Installer Admin Console in your browser and enter the values from the Create GitHub App script output. For the private key, upload the file from the `keys` directory of the script location.
 
 After filling in all fields, click **Continue** at the bottom of the page.