Enhancement: Improve 'Command Not Found' Error Message

[jayambe36]

The current error message for an unknown command is simply "Command not found". This is functional, but it could be more helpful. A better error message would tell the user which command was not recognized and suggest they use the help command.

This makes the application more interactive and guides the user toward discovering the correct commands.

Please assign me this issue to submit this as a PR under the hacktoberfest, hacktoberfest2025, and hacktoberfest-accepted labels.

[anshumanjadiya1102]

Thanks @jayambe36 , Do you want to be a part of this Organization?