docs: add comprehensive README documentation

- Add detailed project overview and features
    - Include installation and setup instructions
    - Document all supported certificate types
    - Add usage examples and API documentation
    - Include security features and deployment guidelines
    - Add project structure and testing information
    - Provide contribution guidelines and support information

README.md

@@ -5,6 +5,7 @@ CertMan is a comprehensive, enterprise-grade certificate management system built
 ## 🚀 Features
 
 ### Core Functionality
+
 - **Certificate Authority Management**: Create and manage root and intermediate CAs
 - **Certificate Lifecycle Management**: Generate, validate, revoke, and renew certificates
 - **Multiple Certificate Types**: Support for web, client, email, code signing, IoT, VPN, and more
@@ -13,6 +14,7 @@ CertMan is a comprehensive, enterprise-grade certificate management system built
 - **Comprehensive Validation**: Built-in validation for certificate requests and attributes
 
 ### Enterprise Features
+
 - **Multi-Organization Support**: Manage certificates across multiple organizations
 - **User Management**: Role-based access control and user authentication
 - **Audit Trail**: Complete logging and tracking of certificate operations
@@ -78,7 +80,7 @@ go build -o certman main.go
 
 ```
 certman/
-├── certificate/           # Certificate management services
+├── certificate/          # Certificate management services
 │   ├── authority.go      # Certificate Authority service
 │   ├── certificate.go    # Certificate service
 │   └── utils/            # Certificate utilities
@@ -86,12 +88,12 @@ certman/
 ├── database/             # Database connection and migrations
 ├── models/               # Data models and types
 ├── repositories/         # Data access layer
-├── storage/             # File storage management
+├── storage/              # File storage management
 ├── utils/                # Utility functions
 ├── data/                 # Certificate and key storage (excluded from git)
-├── main.go              # Application entry point
-├── go.mod               # Go module definition
-└── README.md            # This file
+├── main.go               # Application entry point
+├── go.mod                # Go module definition
+└── README.md             # This file
 ```
 
 ## 🔧 Usage Examples
@@ -156,69 +158,83 @@ certificate, err := certService.CreateCertificate(req)
 CertMan supports a wide range of certificate types for various enterprise use cases:
 
 ### Web & Server Certificates
+
 - `web` - HTTPS/TLS web server certificates
 - `server` - General server certificates
 
 ### Client Certificates
+
 - `client` - Client authentication certificates
 - `user` - User identity certificates
 
 ### Email Certificates
+
 - `email` - S/MIME email certificates
 
 ### Code Signing
+
 - `code` - Code signing certificates
 
 ### IoT & Devices
+
 - `iot` - Internet of Things certificates
 - `device` - Device certificates
 - `sensor` - Sensor device certificates
 
 ### VPN Certificates
+
 - `vpn` - VPN certificates
 - `openvpn` - OpenVPN specific certificates
 - `wireguard` - WireGuard specific certificates
 
 ### Database Certificates
+
 - `database` - Database connection certificates
 - `mysql` - MySQL specific certificates
 - `postgresql` - PostgreSQL specific certificates
 - `mongodb` - MongoDB specific certificates
 
 ### API & Services
+
 - `api` - API service certificates
 - `service` - Microservice certificates
 - `microservice` - Microservice architecture certificates
 
 ### Container & Orchestration
+
 - `docker` - Docker container certificates
 - `kubernetes` - Kubernetes cluster certificates
 - `container` - Container orchestration certificates
 
 ### Cloud & Infrastructure
+
 - `cloud` - Cloud service certificates
 - `aws` - Amazon Web Services certificates
 - `azure` - Microsoft Azure certificates
 - `gcp` - Google Cloud Platform certificates
 
 ### Network & Security
+
 - `network` - Network infrastructure certificates
 - `firewall` - Firewall certificates
 - `proxy` - Proxy server certificates
 - `loadbalancer` - Load balancer certificates
 
 ### Mobile & Applications
+
 - `mobile` - Mobile application certificates
 - `android` - Android specific certificates
 - `ios` - iOS specific certificates
 - `app` - Application certificates
 
 ### Document & File Signing
+
 - `document` - Document signing certificates
 - `pdf` - PDF signing certificates
 - `office` - Microsoft Office signing certificates
 
 ### Specialized Certificates
+
 - `timestamp` - Time stamping certificates
 - `ocsp` - OCSP responder certificates
 - `custom` - Custom certificate types
@@ -253,12 +269,14 @@ go test -cover ./...
 The application provides a comprehensive API for certificate management operations. Key endpoints include:
 
 - **Certificate Authority Management**
+
   - Create Root CA
   - Create Intermediate CA
   - List CAs
   - Get CA Details
 
 - **Certificate Management**
+
   - Generate Certificate
   - Validate Certificate
   - Revoke Certificate