Run incognito/private commands for Bash and Zsh
Bash
Simply put a space before the command and it won't be saved to `~/.bash_history`. E.g. ` qrencode -o out.png "Some secret text"`
Zsh
Enable the following option to be able to run private commands by adding a space before and prevent it from being saved to `~/.zsh_history`.
setopt HIST_IGNORE_SPACE
