docs: add comprehensive MkDocs documentation

- Create docs folder with complete documentation structure
- Add mkdocs.yml configuration with Material theme
- Add comprehensive documentation pages:
  - Getting started (installation, quick start)
  - User guides (commands, platforms, output formats)
  - Integration guides (Nornir, Ansible, CI/CD)
  - Development guides (contributing, testing, code quality)
  - API reference and changelog
- Add mkdocs dependencies to pyproject.toml
- Documentation includes:
  - Multi-platform examples
  - Integration patterns
  - Best practices
  - Troubleshooting guides
  - Code examples

Author: claude

docs/api-reference.md

@@ -0,0 +1,289 @@
+# API Reference
+
+This page provides detailed API documentation for hier-config-cli's Python modules.
+
+## Command-Line Interface
+
+### Main CLI Group
+
+::: hier_config_cli.cli
+    options:
+      show_root_heading: true
+      show_source: true
+
+## Core Functions
+
+### Configuration Processing
+
+::: hier_config_cli.process_configs
+    options:
+      show_root_heading: true
+      show_source: true
+
+### Output Formatting
+
+::: hier_config_cli.format_output
+    options:
+      show_root_heading: true
+      show_source: true
+
+::: hier_config_cli.get_output_text
+    options:
+      show_root_heading: true
+      show_source: true
+
+### Logging
+
+::: hier_config_cli.setup_logging
+    options:
+      show_root_heading: true
+      show_source: true
+
+## Commands
+
+### Remediation Command
+
+::: hier_config_cli.remediation
+    options:
+      show_root_heading: true
+      show_source: true
+
+### Rollback Command
+
+::: hier_config_cli.rollback
+    options:
+      show_root_heading: true
+      show_source: true
+
+### Future Command
+
+::: hier_config_cli.future
+    options:
+      show_root_heading: true
+      show_source: true
+
+### List Platforms Command
+
+::: hier_config_cli.list_platforms
+    options:
+      show_root_heading: true
+      show_source: true
+
+### Version Command
+
+::: hier_config_cli.version
+    options:
+      show_root_heading: true
+      show_source: true
+
+## Constants
+
+### Platform Mapping
+
+The `PLATFORM_MAP` dictionary maps platform names to `hier_config.Platform` enum values:
+
+```python
+PLATFORM_MAP = {
+    "ios": Platform.CISCO_IOS,
+    "nxos": Platform.CISCO_NXOS,
+    "iosxr": Platform.CISCO_XR,
+    "eos": Platform.ARISTA_EOS,
+    "junos": Platform.JUNIPER_JUNOS,
+    "vyos": Platform.VYOS,
+    "fortios": Platform.FORTINET_FORTIOS,
+    "generic": Platform.GENERIC,
+    "hp_comware5": Platform.HP_COMWARE5,
+    "hp_procurve": Platform.HP_PROCURVE,
+}
+```
+
+## Type Definitions
+
+### Common Types
+
+```python
+from pathlib import Path
+from typing import Optional, Union
+
+# Configuration path types
+ConfigPath = Union[str, Path]
+
+# Output format types
+OutputFormat = Literal["text", "json", "yaml"]
+
+# Operation types
+Operation = Literal["remediation", "rollback", "future"]
+```
+
+## Usage Examples
+
+### Programmatic Usage
+
+While hier-config-cli is primarily a CLI tool, you can use its functions programmatically:
+
+```python
+from hier_config_cli import process_configs, format_output
+from pathlib import Path
+
+# Process configurations
+result, platform = process_configs(
+    platform_str="ios",
+    running_config_path="configs/running.conf",
+    generated_config_path="configs/intended.conf",
+    operation="remediation",
+)
+
+# Format output
+output = format_output(
+    hconfig=result,
+    platform=platform,
+    output_format="text",
+)
+
+print(output)
+```
+
+### Custom Integration
+
+```python
+import subprocess
+import json
+from pathlib import Path
+
+def generate_remediation(
+    platform: str,
+    running_config: Path,
+    intended_config: Path,
+) -> dict:
+    """Generate remediation using hier-config-cli.
+
+    Args:
+        platform: Platform name
+        running_config: Path to running config
+        intended_config: Path to intended config
+
+    Returns:
+        Remediation data as dictionary
+
+    Raises:
+        subprocess.CalledProcessError: If command fails
+    """
+    result = subprocess.run(
+        [
+            "hier-config-cli",
+            "remediation",
+            "--platform", platform,
+            "--running-config", str(running_config),
+            "--generated-config", str(intended_config),
+            "--format", "json",
+        ],
+        capture_output=True,
+        text=True,
+        check=True,
+    )
+
+    return json.loads(result.stdout)
+
+# Usage
+remediation = generate_remediation(
+    platform="ios",
+    running_config=Path("configs/running.conf"),
+    intended_config=Path("configs/intended.conf"),
+)
+
+for command in remediation["config"]:
+    print(command)
+```
+
+## Error Handling
+
+### Exception Types
+
+hier-config-cli uses `click.ClickException` for all user-facing errors:
+
+```python
+from click import ClickException
+
+try:
+    result = process_configs(
+        platform_str="invalid",
+        running_config_path="running.conf",
+        generated_config_path="intended.conf",
+        operation="remediation",
+    )
+except ClickException as e:
+    print(f"Error: {e.message}")
+```
+
+### Common Exceptions
+
+| Exception | Cause | Message Example |
+|-----------|-------|-----------------|
+| `ClickException` | Unknown platform | "Unknown platform: invalid_platform" |
+| `ClickException` | File not found | "Running config file not found: path/to/file" |
+| `ClickException` | Permission denied | "Permission denied reading running config: path/to/file" |
+| `ClickException` | Parsing error | "Error parsing configuration: [details]" |
+
+## Exit Codes
+
+| Code | Meaning |
+|------|---------|
+| 0 | Success |
+| 1 | Error occurred |
+
+## Environment Variables
+
+hier-config-cli doesn't use environment variables directly, but respects standard Python environment variables:
+
+| Variable | Purpose |
+|----------|---------|
+| `PYTHONPATH` | Python module search path |
+| `PYTHONDONTWRITEBYTECODE` | Disable .pyc files |
+
+## Logging
+
+### Log Levels
+
+Control logging verbosity with the `-v` flag:
+
+```bash
+# WARNING level (default)
+hier-config-cli remediation ...
+
+# INFO level
+hier-config-cli -v remediation ...
+
+# DEBUG level
+hier-config-cli -vv remediation ...
+```
+
+### Log Format
+
+```
+LEVEL: message
+```
+
+Examples:
+```
+INFO: Using platform: ios
+INFO: Reading running config from: running.conf
+INFO: Reading generated config from: intended.conf
+INFO: Parsing configurations
+INFO: Generating remediation configuration
+```
+
+## Related Documentation
+
+- [Commands Reference](commands.md) - Detailed command documentation
+- [Integration Guide](integration/index.md) - Integration examples
+- [Development Guide](development/contributing.md) - Contributing guidelines
+
+## External Dependencies
+
+hier-config-cli depends on:
+
+- [hier-config](https://github.com/netdevops/hier_config) - Core configuration analysis
+- [click](https://click.palletsprojects.com/) - CLI framework
+- [PyYAML](https://pyyaml.org/) - YAML support
+
+Refer to their documentation for advanced usage and features.