Add zsh plugin

closes #18

git-recent.plugin.zsh

@@ -0,0 +1 @@
+export PATH=$(dirname $0):${PATH}

readme.md

@@ -15,11 +15,15 @@ Optionally, add `-n<int>` to see the most recent `<n>` branches
 
 If you're a Windows user, you need to use [Git Bash](https://git-scm.com/downloads) or similar shell in order to effectively use this utility.
 
-### Installation
+## Installation
+
+### Basic install
 
 You can add the `git-recent` location to your path (e.g. add the directory to your `PATH` environment
 or copy `git-recent` into an existing included path like `/usr/local/bin` or `~/bin/`).
 
+### Install via NPM:
+
 You can use also `npm` to install the global binary:
 
     npm install --global git-recent
@@ -28,6 +32,36 @@ On Mac, you can install with homebrew:
 
     brew install git-recent
 
+### ZSH
+
+#### [Antigen](https://github.com/zsh-users/antigen)
+
+Add `antigen bundle paulirish/git-recent` to your `.zshrc` with your other bundle
+commands.
+
+Antigen will handle cloning the plugin for you automatically the next time you
+start zsh, and periodically checking for updates to the git repository. You can
+also add the plugin to a running zsh with `antigen bundle paulirish/git-recent`
+for testing before adding it to your `.zshrc`.
+
+#### [Oh-My-Zsh](http://ohmyz.sh/)
+
+1. `git clone https://github.com/paulirish/git-recent.git $ZSH_CUSTOM/plugins/git-recent`
+1. Add `git-recent` to your plugin list - edit `~/.zshrc` and change
+   `plugins=(...)` to `plugins=(... git-recent)`
+
+#### [Zgen](https://github.com/tarjoilija/zgen)
+
+Add `zgen load paulirish/git-recent` to your .zshrc file in the same function
+you're doing your other `zgen load` calls in. ZGen will take care of cloning
+the repository the next time you run `zgen save`, and will also periodically
+check for updates to the git repository.
+
+#### [zplug](https://github.com/zplug/zplug)
+
+`zplug "paulirish/git-recent", as:plugin`
+
+
 ## If you like this you may also be interested in...
 
 - [`git open`](https://github.com/paulirish/git-open) - Open the repo website in your browser