This reverts to the original (working) version from 2017. During the most recent refactor to use the `_bash_it_homebrew_check` helper method, it was overlooked that `${BASH_IT_HOMEBREW_PREFIX}/nvm.sh` is not the equivalent to `$(brew --prefix nvm)/nvm.sh` since `BASH_IT_HOMEBREW_PREFIX` is set from `brew --prefix` instead of `brew --prefix nvm`.
Use new function `_bash_it_homebrew_check()` in existing plugins and completions which look for Homebrew.
Alsö, use `$OSTYPE` instead of calling external `uname` binary.
add about-plugin metadata
chmod -x plugins
cleanup filenames to standardize on x.plugin.bash format
only plugin files intended to be executable from the command line should
contain a shebang line, and should be a+x.
Brian Phillips
John D Pell
Nils Winkler
Andrew Ochsner
shine
Kyle VanderBeek
Benjamin Brombach
Erich Smith
Antono Vasiljev
Antono Vasiljev