* feat: add reverse option to git-brv
When there are a large amount of branches it is often useful to see the
most recent branches last as they end up closer to the prompt. This adds
a new --reverse / -r option and an environment variable to set the
default behavior (GIT_BRV_REVERSE).
* git-brv: change to git option instead of environment variable and fix typo
* wrap git option in backticks for git-brv and fix git-feature title
* update git-feature docs
* fix missing breaks in git-feature.md
