Log message:
shells/yash: import pkg

Yash, yet another shell, is a POSIX-compliant command line shell written
in C99 (ISO/IEC 9899:1999). Yash is intended to be the most POSIX -
compliant shell in the world while supporting features for daily
interactive and scripting use. Notable features are:

- Global aliases
- Arrays
- Socket redirection, pipeline redirection, and process redirection
- Brace expansion and extended globbing
- Fractional numbers in arithmetic expansion
- Prompt command and command-not-found handler
- Command line completion with predefined completion scripts for more
  than 100 commands
- Command line prediction based on command history

By Paolo Vincenzo Olivo in wip