inko-lang for packer.nu

Features

• add the ivm bin directory to the PATH
• inko tab complete
• ivm tab complete
• ipm tab complete
  • complete packages (from a local "common package" list)
• std-lib documentation quick-access (inko docs STD-LIB-MODULE)

Known issues

• since nu is buggy when importing extern statements with prefix its implemented a bit weird.
• nu currently doesn't have a good method to complete subcommands AND a main command
  • usually inko FILE runs it, but only inko run FILE has completion
  • no inko --version completion