docs: Add server configuration manual and manpages

Create comprehensive documentation for bssh-server and bssh-keygen:

Man Pages:
- docs/man/bssh-server.8 - System administration manual for bssh-server
- docs/man/bssh-keygen.1 - User manual for SSH key generation tool

Documentation:
- docs/README.md - Documentation index and quick links
- docs/quick-start.md - Getting started guide
- docs/container-deployment.md - Docker and Kubernetes deployment guide
- docs/security.md - Security best practices and hardening checklist
- docs/audit-logging.md - Audit logging setup and SIEM integration

All documentation includes:
- Complete configuration reference
- CLI options and examples
- Best practices and security considerations
- Integration examples (OTEL, Logstash, ELK, Grafana)
- Troubleshooting guides

Closes #144

Author: inureyes

docs/README.md

@@ -0,0 +1,158 @@
+# bssh Documentation
+
+Welcome to the bssh documentation. This documentation covers both the bssh client and bssh-server.
+
+## Quick Links
+
+- **[Quick Start Guide](./quick-start.md)** - Get bssh-server running in minutes
+- **[Server Configuration](./architecture/server-configuration.md)** - Complete configuration reference
+- **[Security Guide](./security.md)** - Security best practices
+- **[Container Deployment](./container-deployment.md)** - Docker and Kubernetes deployment
+
+## Documentation Index
+
+### Getting Started
+
+| Document | Description |
+|----------|-------------|
+| [Quick Start](./quick-start.md) | Installation and first run guide |
+| [Container Deployment](./container-deployment.md) | Docker and Kubernetes deployment |
+
+### Server Administration
+
+| Document | Description |
+|----------|-------------|
+| [Server Configuration](./architecture/server-configuration.md) | Complete configuration reference |
+| [Security Guide](./security.md) | Security best practices and hardening |
+| [Audit Logging](./audit-logging.md) | Audit logging setup and integration |
+
+### Client Documentation
+
+| Document | Description |
+|----------|-------------|
+| [CLI Interface](./architecture/cli-interface.md) | Command-line interface documentation |
+| [Interactive Mode](./architecture/interactive-mode.md) | TUI and interactive shell mode |
+| [SSH Jump Hosts](./architecture/ssh-jump-hosts.md) | ProxyJump and jump host support |
+| [Port Forwarding](./architecture/ssh-port-forwarding.md) | Local, remote, and dynamic forwarding |
+
+### Migration Guides
+
+| Document | Description |
+|----------|-------------|
+| [pdsh Migration](./pdsh-migration.md) | Migrating from pdsh to bssh |
+| [pdsh Examples](./pdsh-examples.md) | pdsh-style command examples |
+| [pdsh Options](./pdsh-options.md) | pdsh option compatibility |
+
+### Architecture
+
+| Document | Description |
+|----------|-------------|
+| [Architecture Overview](./architecture/README.md) | System architecture overview |
+| [SSH Client](./architecture/ssh-client.md) | SSH client implementation |
+| [SSH Config Parser](./architecture/ssh-config-parser.md) | SSH config file parsing |
+| [Executor](./architecture/executor.md) | Parallel execution engine |
+| [TUI](./architecture/tui.md) | Terminal user interface |
+| [Exit Codes](./architecture/exit-code-strategy.md) | Exit code handling |
+
+### Man Pages
+
+Man pages are located in [docs/man/](./man/):
+
+| Man Page | Section | Description |
+|----------|---------|-------------|
+| [bssh(1)](./man/bssh.1) | 1 | bssh client manual |
+| [bssh-server(8)](./man/bssh-server.8) | 8 | bssh-server administration manual |
+| [bssh-keygen(1)](./man/bssh-keygen.1) | 1 | SSH key generation tool manual |
+
+### Shell Integration
+
+| Document | Description |
+|----------|-------------|
+| [Shell Config](./shell-config/README.md) | Shell integration and completion |
+
+## Installation
+
+### From Binary
+
+```bash
+# Download and install binaries
+curl -LO https://github.com/lablup/bssh/releases/latest/download/bssh-linux-amd64.tar.gz
+tar xzf bssh-linux-amd64.tar.gz
+sudo mv bssh bssh-server bssh-keygen /usr/local/bin/
+```
+
+### From Source
+
+```bash
+git clone https://github.com/lablup/bssh.git
+cd bssh
+cargo build --release
+sudo cp target/release/bssh /usr/local/bin/
+sudo cp target/release/bssh-server /usr/local/bin/
+sudo cp target/release/bssh-keygen /usr/local/bin/
+```
+
+### Man Page Installation
+
+```bash
+sudo install -Dm644 docs/man/bssh.1 /usr/share/man/man1/bssh.1
+sudo install -Dm644 docs/man/bssh-keygen.1 /usr/share/man/man1/bssh-keygen.1
+sudo install -Dm644 docs/man/bssh-server.8 /usr/share/man/man8/bssh-server.8
+sudo mandb
+```
+
+## Components
+
+### bssh (Client)
+
+A high-performance SSH client that can be used as a drop-in replacement for OpenSSH while also providing parallel execution capabilities for cluster management.
+
+```bash
+# Single host (SSH compatibility)
+bssh user@host
+
+# Multiple hosts
+bssh -H host1,host2,host3 'uptime'
+
+# Using clusters
+bssh -C mycluster 'hostname'
+```
+
+### bssh-server
+
+A lightweight SSH server designed for container environments with built-in audit logging, file transfer filtering, and comprehensive security controls.
+
+```bash
+# Generate configuration
+bssh-server gen-config -o /etc/bssh/server.yaml
+
+# Generate host key
+bssh-server gen-host-key -t ed25519 -o /etc/bssh/ssh_host_ed25519_key
+
+# Start server
+bssh-server -c /etc/bssh/server.yaml
+```
+
+### bssh-keygen
+
+SSH key generation tool compatible with OpenSSH key formats.
+
+```bash
+# Generate Ed25519 key (recommended)
+bssh-keygen
+
+# Generate RSA key
+bssh-keygen -t rsa -b 4096
+
+# Generate with custom comment
+bssh-keygen -C "user@hostname"
+```
+
+## Support
+
+- **Issues**: [GitHub Issues](https://github.com/lablup/bssh/issues)
+- **Repository**: [GitHub](https://github.com/lablup/bssh)
+
+## License
+
+Apache License 2.0