Add local admin login alongside Entra ID authentication

README.md

@@ -23,16 +23,32 @@ A Python web application built with Flask that automatically renames PDF files b
 **Detailed setup instructions**: See [ENTRA_SETUP.md](ENTRA_SETUP.md) for comprehensive step-by-step guide to configure Microsoft Entra ID authentication.
 
 ### Quick Setup:
-1. Register application in Azure Portal
-2. Get Tenant ID, Client ID, and Client Secret
+1. Register application in Azure Portal (optional for admin login)
+2. Get Tenant ID, Client ID, and Client Secret (for Entra login)
 3. Set environment variables:
    ```bash
+   # For Entra ID login (optional)
    export TENANT_ID="your-tenant-id"
    export CLIENT_ID="your-client-id"
    export CLIENT_SECRET="your-client-secret"
+   
+   # For admin login
+   export ADMIN_USERNAME="admin"
+   export ADMIN_PASSWORD="your-secure-password"
+   
+   # Required
    export SECRET_KEY="your-random-secret-key"
    ```
 
+## Authentication
+
+The application supports two authentication methods:
+
+1. **Microsoft Entra ID**: OAuth2 authentication with Azure AD
+2. **Admin Login**: Local username/password authentication
+
+Users can choose their preferred login method on the login page.
+
 ## Installation
 
 1. **Clone the repository**: