Add comprehensive Entra ID setup guide

README.md

@@ -20,23 +20,12 @@ A Python web application built with Flask that automatically renames PDF files b
 
 ## Microsoft Entra ID Setup
 
-1. **Register an application** in Azure Portal:
-   - Go to Azure Active Directory > App registrations > New registration
-   - Name: PDF Renamer App
-   - Supported account types: Accounts in this organizational directory only
-   - Redirect URI: `http://localhost:3000/auth` (for local development)
+**Detailed setup instructions**: See [ENTRA_SETUP.md](ENTRA_SETUP.md) for comprehensive step-by-step guide to configure Microsoft Entra ID authentication.
 
-2. **Configure authentication**:
-   - In the app registration, go to Authentication
-   - Add redirect URI if not set: `http://localhost:3000/auth`
-   - Enable "Access tokens" and "ID tokens" if needed
-
-3. **Get credentials**:
-   - Client ID: From Overview page
-   - Tenant ID: From Overview page
-   - Client Secret: Go to Certificates & secrets > New client secret
-
-4. **Set environment variables**:
+### Quick Setup:
+1. Register application in Azure Portal
+2. Get Tenant ID, Client ID, and Client Secret
+3. Set environment variables:
    ```bash
    export TENANT_ID="your-tenant-id"
    export CLIENT_ID="your-client-id"