Add documentation for integrating CodeRabbit with self-hosted GitHub

Author: hasit

docs/integrations/setf-hosted-github.md

@@ -0,0 +1,65 @@
+---
+title: CodeRabbit for Self-Hosted GitHub
+description: Integrate CodeRabbit with your Self-Hosted GitHub instance.
+sidebar_label: Self-Hosted GitHub
+---
+
+This page guides you through the process of integrating your CodeRabbit with your self-hosted GitHub instance.
+
+1. [Create a GitHub App](https://docs.github.com/en/apps/creating-github-apps/registering-a-github-app/registering-a-github-app) in your Organization or User account.
+
+    - Set the following Repository permissions:
+        - Checks: Read-only
+        - Contents: Read and write
+        - Discussions: Read-only
+        - Issues: Read & write
+        - Metadata: Read-only
+        - Pull requests: Read & write
+
+    - Set the following Organization permissions:
+        - Members: Read-only
+
+    - Set the following events:
+        - Meta
+        - Issue comment
+        - Issues
+        - Label
+        - Public
+        - Pull request
+        - Pull request review
+        - Pull request review comment
+        - Pull request review thread
+        - Push
+        - Release
+
+2. Get the following information from the GitHub App:
+
+    - App ID
+    - Client ID
+    - Client Secret
+    - Webhook Secret
+
+3. Prepare `.env` file with the following information:
+
+    ```bash
+    OPENAI_API_KEYS=<openai-key>
+
+    TEMP_PATH=/cache
+
+    AST_GREP_RULES_PATH=/home/jailuser/ast-grep-rules
+    AST_GREP_ESSENTIALS=ast-grep-essentials
+
+    GH_WEBHOOK_SECRET=<webhook-secret>
+    GITHUB_APP_CLIENT_ID=<github-app-client-id>
+    GITHUB_APP_CLIENT_SECRET=<github-app-client-secret>
+    GITHUB_APP_ID=<github-app-id>
+    GITHUB_APP_PEM_FILE=<flattened-pem-file>
+    ```
+
+    > Note: For the `GITHUB_APP_PEM_FILE`, you need to flatten the PEM file by replacing newlines with `\n`.
+
+4. Pull the CodeRabbit Docker image. The CodeRabbit Docker image is not available for public use. Please contact us at <[email protected]> for access.
+
+5. Host the image on a server, serverless function, or a container environment and expose the port `8080`.
+
+6. Install the GitHub App on your GitHub organization or user account and point the Webhook URL to the hosted CodeRabbit instance, for example, `127.0.0.1:8080/github_webhooks`. GitHub will send events to the CodeRabbit instance.