Backup existing dotfiles before overwriting

[rsvinicius]

Description

Add functionality to backup existing dotfiles before they are overwritten, allowing users to revert changes if needed.

Tasks

• Add --backup or -b flag to enable backup mode
• Implement backup logic to create copies with timestamp or version suffix
• Add option to specify backup location
• Add restore functionality to revert to backed-up files
• Update documentation with backup/restore examples

Example Use Cases

# Enable backup of existing dotfiles
dotme --backup https://github.com/user/repo

# Specify backup location
dotme --backup --backup-dir=~/dotfiles-backup https://github.com/user/repo

# Restore from backup
dotme --restore=20250404-123045

Benefits

• Provides safety net for users when applying new dotfiles
• Allows easy reverting to previous configurations
• Reduces risk when trying new dotfile repositories

Target Version

v0.2.0