Initial release of checkrc

This is the first official release of checkrc. It includes the following features:

• Command-line validation tool for FreeBSD /etc/rc.conf file.
• Ensures that configuration settings are valid for system boot.
• Outputs a success message when no issues are found.
• Easy-to-use command: ./checkrc /etc/rc.conf.
• Provides a better debugging experience than the traditional sh -n /etc/rc.conf command.

Contribute by forking the repository, creating a new branch, and submitting pull requests.