add ratelimiting to README

README.md

@@ -9,6 +9,7 @@ A lightweight user management system for LDAP, implemented using Flask. This app
 - **User Unregistration**: Users can remove themselves from the LDAP system.
 - **Captcha Protection**: Uses a custom captcha mechanism to mitigate bot registrations.
 - **LDAP Integration**: Directly interacts with LDAP for all credential and user management tasks.
+- **Rate limiting** (new): Setting rate limiting for user registration.
 
 ## Prerequisites
 
@@ -37,6 +38,8 @@ A lightweight user management system for LDAP, implemented using Flask. This app
    - `LDAPPASS`: Admin password for LDAP operations.
    - `USERBASE`: The base DN for users.
    - `CAPTCHA_PATH`: Path where captcha images are stored.
+   - `PERIOD`: Time period after which the rate limiting counter resets
+   - `LIMIT`: Number of allowed user registrations in the given time PERIOD
 
 4. **Setup Captcha script**:
    Ensure the `captcha.sh` script is available in `/usr/local/bin/` and is executable.