Add config for easier command line usage

Added

• You can save and run project configurations (#2)
  • code_sync --register <project> prompts for project configuration and saves to config file
  • code_sync <project> runs code_sync with the saved project configuration
  • code_sync --list lists registered projects
  • You can also still run code_sync the old way, specifying the local_dir, remote_dir, etc manually.