Update README

Author: James Sherlock

README.md

@@ -1,3 +1,36 @@
 # SwiftyProvisioningProfile
 
-A description of this package.
+This library provides a way to decode a `.mobileprovision` file into a Swift model.
+
+#### Installation
+
+The recommended installation is via Swift Package Manager, you'll want to update your `Package.swift` with a new dependency:
+
+```swift
+import PackageDescription
+
+let package = Package(
+    name: "YourAwesomeSoftware",
+    dependencies: [
+        .package(url: "https://github.com/Sherlouk/SwiftProvisioningProfile.git", from: "1.0.0")
+    ]
+)
+```
+
+There are open issues to handle CocoaPods and Carthage installation, if people want it then I'm willing to support it!
+
+#### Usage
+
+```swift
+// 1. Import the library
+import SwiftyProvisioningProfile
+
+// 2. Load your provisioning profile's file data
+let profileData = try Data(contentsOf: ...)
+
+// 3. Parse it
+let profile = try ProvisioningProfile.parse(from: profileData)
+
+// 4. Use it
+print(profile.uuid)
+```