Add README for email validation catalog client script

Author: Dhruvyadav2000

Client-Side Components/Catalog Client Script/Email Validation/readme_email_validation.md

@@ -0,0 +1,29 @@
+# ServiceNow Email Validation Catalog Client Script
+
+## Overview
+Client-side validation script for ServiceNow catalog items to ensure proper email format in user input fields.
+
+## Features
+- Real-time email format validation
+- Form submission prevention for invalid emails
+- User-friendly error messages
+- Standard email pattern validation
+
+## Implementation
+1. Navigate to **Service Catalog > Catalog Client Scripts**
+2. Create new script and select catalog item
+3. Choose script type: **onSubmit** or **onChange**
+4. Replace `email_field_name` with your field variable name
+5. Save and activate
+
+## Validation Rules
+- Required format: `user@domain.com`
+- Accepts: letters, numbers, dots, underscores, hyphens
+- Minimum 2-character domain extension
+
+## Script Types
+- **onSubmit**: Validates before form submission
+- **onChange**: Real-time validation as user types
+
+## Usage
+Best practice: Use both scripts for comprehensive validation and better user experience.