Update README.md

Author: grdsdev

README.md

@@ -1,3 +1,25 @@
-# functions-swift
+# `functions-swift`
 
-A description of this package.
+Swift Client library to interact with Supabase Functions.
+
+## Usage
+
+```swift
+let client = FunctionsClient(
+  url: URL(string: "https://project-id.supabase.com/functions/v1")!,
+  headers: [
+    "apikey": "project-api-key"
+  ]
+)
+
+struct Response: Decodable {
+  let message: String
+}
+
+let response: Response = try await client.invoke(
+  functionName: "hello-world",
+  invokeOptions: FunctionInvokeOptions(body: ["name": "Functions"])
+)
+
+assert(response.message = "Hello Functions")
+```