README update

Author: darya-varabei

README.md

@@ -14,7 +14,7 @@ A lightweight Swift package for interacting with OpenAI's `gpt-image-1` model to
 
 - iOS 15.0+ / macOS 12.0+
 - Swift 5.7+
-- Valid OpenAI API key
+- Valid OpenAI API key with account verification
 - Network permission enabled
 
 ## 📦 Installation
@@ -23,4 +23,49 @@ Add to your project via **Swift Package Manager**:
 
 ```swift
 .package(url: "https://github.com/darya-varabei/OpenAIImageClient.git", from: "1.0.0")
+```
 
+## 💡 Usage
+
+For image generation (generate image from prompt):
+
+```swift
+    private let client = OpenAIImageClient(apiKey: "sk-***") // recommended to NOT store in code for production apps
+
+    let prompt = "Generate an image of a spaceship"
+    
+    do {
+        let results = try await client.generateImage(prompt: prompt, size: .x1536x1024)
+        if let data = results.first?.data {
+            image = UIImage(data: data)
+        }
+    } catch {
+        self.error = error.localizedDescription
+    }
+```
+
+
+For image edit (edit provided images according to provided prompt):
+
+```swift
+    private let client = OpenAIImageClient(apiKey: "sk-***") // recommended to NOT store in code for production apps
+    
+    let prompt = "Make the room look like a spaceship"
+    
+    let images = [UIImage(named: "result")!.pngData()!]
+    
+    do {
+        let results = try await client.editImages(images: images, prompt: prompt)
+        if let data = results.first {
+            image = UIImage(data: data)
+        }
+    } catch {
+        self.error = error.localizedDescription
+    }
+```
+
+## 🔮 To be added
+
+- Test coverage
+- More OpenAI requst parameters
+- Anything else proposed by community :)