Update readme with installation instructions

README.md

@@ -1,15 +1,51 @@
 # Either
 
+[![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage)
 [![Version](https://img.shields.io/cocoapods/v/Either.svg?style=flat)](http://cocoapods.org/pods/Either)
 [![License](https://img.shields.io/cocoapods/l/Either.svg?style=flat)](http://cocoapods.org/pods/Either)
 [![Platform](https://img.shields.io/cocoapods/p/Either.svg?style=flat)](http://cocoapods.org/pods/Either)
 
-Either is an implementation of Haskell's `Either` type in Swift. The current
+Either is an implementation of [Haskell's `Either`
+type](https://hackage.haskell.org/package/base-4.9.1.0/docs/Data-Either.html) in Swift. The current
 version (1.x) is compatible with Swift 3.
+
 ## Usage
 
+Either is an enum consisting of either a .right or a .left, each with an
+associated value. It's commonly used in Haskell for error handling, with Right
+holding a success value and Left holding a failure value. This is a more
+functional way of handling errors compared to throwing and catching. 
+
+The best way to see this library in action is by looking at the tests. Each
+function is also commented upon in the Either source. 
+
 ## Installation
 
+### Carthage
+Add the following to your Cartfile:
+
+```
+github "runkmc/either"
+```
+
+Then run `carthage update`.
+
+### CocoaPods
+
+Add the following to your Podfile:
+
+```
+pod 'Either'
+```
+
+You will also need to make sure you're opting into using frameworks:
+
+```
+use_frameworks!
+```
+
+Then run `pod install`.
+
 ## Author
 
 Kevin McGladdery, [email protected]