Add comprehensive documentation

[errnair]

Summary

Add comprehensive documentation covering all modernized scripts, migration paths, and usage examples.

Documentation Added

README.md Updates

• Complete script catalog with all 25+ scripts
• Detailed feature descriptions for each script
• Quick start examples with accurate syntax
• OS compatibility matrix
• Security best practices documentation
• Common library function reference
• Environment variable configuration guide

MIGRATION.md

• Complete mapping table of old to new script locations
• Breaking changes documentation
• Before/after migration examples for each script
• Environment variable changes
• Feature enhancements for each migrated script
• Testing guidelines for migration
• Timeline and migration checklist

EXAMPLES.md

• Installation workflows (web stack, CI/CD, monitoring, Salt, proxy)
• Backup and recovery procedures (daily backups, database integration, restore, remote backup)
• Security hardening (SELinux, firewall, SSL, password management)
• Monitoring and troubleshooting (system stats, CPU, benchmarking, port checks)
• Automation with cron (backup schedules, monitoring, certificate renewal)
• Integration with Ansible and SaltStack
• Multi-server deployment examples
• Best practices section

CHANGELOG.md

• Complete 2.0.0 release notes
• Detailed list of all added features
• Infrastructure improvements documented
• All 25+ scripts cataloged with features
• Breaking changes clearly marked
• Deprecated script locations listed
• Security improvements documented
• Fixed issues documented

File Permissions

Updated script file permissions to executable:

• server_management/change_hostname.sh
• server_management/system_stats.sh
• utilities/dirbackup.sh
• utilities/passgen.sh
• utilities/webpagedl.sh

Validation

• All scripts pass bash syntax validation
• All Python scripts compile successfully
• Documentation examples reference actual script capabilities
• File structure matches repository layout