feature: implemented and tested rename command

[Kaveeshakavindi]

Changes Included

Added: com.mycmd.commands.Rename.java

1. Implements the rename command using Java NIO (Files.move()).
2. Supports renaming both files and directories.
3. Uses ShellContext.resolvePath() for relative path resolution.
4. Displays success or error messages to the user.
5. Includes usage and description metadata.

Modified:

1. App.java (or equivalent main shell entry file)
2. Registered the new rename command in the command map or registry.
3. Added optional alias ren → rename for command consistency.

Testing

1. Verified file renaming in current directory and subdirectories.

[github-actions]

🚀 Hi @Kaveeshakavindi!

Thank you for contributing to MyCMD. A maintainer will review your PR shortly. 🎉

[github-actions]

🚀 Hi @Kaveeshakavindi!

Thank you for contributing to MyCMD. A maintainer will review your PR shortly. 🎉