[GNU ELPA] Shell-Command+ version 2.3.1

[ELPA update]

Version 2.3.1 of package Shell-Command+ has just been released in GNU ELPA.
You can now find it in M-x package-list RET.

Shell-Command+ describes itself as:
  An extended shell-command

More at https://elpa.gnu.org/packages/shell-command+.html

Recent NEWS:

Version 2.3.0 (15Oct21)

- Add rgrep to shell-command+-substitute-alist
- Fix shell-command+-substitute-alist customization type
- Skip environmental variables when parsing a command
- Check if command is being piped, in which case command
  substitution is avoided.
- Fix persistent sudo bug, where any command after a sudo
  substitute would try to run as root
- Improve command tokenization performance slightly.