Update README.md to correct method signatures (#38)

* Update README.md to correct method signatures

* Update README.md

* try await

Author: leoromanovsky

README.md

@@ -4,6 +4,8 @@
 
 [Eppo](https://www.geteppo.com/) is a modular flagging and experimentation analysis tool. Eppo's iOS SDK is built to make assignments for single user client applications. Before proceeding you'll need an Eppo account.
 
+The [primary documentation](https://docs.geteppo.com/sdks/client-sdks/ios/) explains the overall architecture and in-depth usage guides.
+
 ## Features
 
 - Feature gates
@@ -34,7 +36,7 @@ It is recommended to wrap initialization in a `Task` block in order to perform n
 
 ```swift
 Task {
-    try await EppoClient.initialize(apiKey: "SDK-KEY-FROM-DASHBOARD");
+    try await EppoClient.initialize(sdkKey: "SDK-KEY-FROM-DASHBOARD");
 }
 ```
 
@@ -44,10 +46,10 @@ Assignment is a synchronous operation.
 
 ```swift
 let assignment = try eppoClient.getStringAssignment(
-    "new-user-onboarding",
-    user.id,
-    user.attributes,
-    "control"
+    flagKey: "new-user-onboarding",
+    subjectKey: user.id,
+    subjectAttributes: user.attributes,
+    defaultValue: "control"
 );
 ```
 
@@ -62,10 +64,10 @@ public class AssignmentObserver: ObservableObject {
         do {
             // Use the shared instance after it has been configured.
             self.assignment = try EppoClient.shared().getStringAssignment(
-                "new-user-onboarding",
-                user.id,
-                user.attributes,
-                "control"
+                flagKey: "new-user-onboarding",
+                subjectKey: user.id,
+                subjectAttributes: user.attributes,
+                defaultValue: "control"
             );
         } catch {
             self.assignment = nil
@@ -85,12 +87,12 @@ public class AssignmentObserver: ObservableObject {
         Task {
             do {
                 // The initialization method has controls to maintain a single instance.
-                try await EppoClient.initialize(apiKey: "SDK-KEY-FROM-DASHBOARD");
+                try await EppoClient.initialize(sdkKey: "SDK-KEY-FROM-DASHBOARD");
                 self.assignment = try EppoClient.shared().getStringAssignment(
-                    "new-user-onboarding",
-                    user.id,
-                    user.attributes,
-                    "control"
+                    flagKey: "new-user-onboarding",
+                    subjectKey: user.id,
+                    subjectAttributes: user.attributes,
+                    defaultValue: "control"
                 );
             } catch {
                 self.assignment = nil
@@ -175,7 +177,7 @@ func segmentAssignmentLogger(assignment: Assignment) {
     )
 }
 
-eppoClient = EppoClient("mock-sdk-key", assignmentLogger: segmentAssignmentLogger)
+eppoClient = try await EppoClient.initialize(sdkKey: "mock-sdk-key", assignmentLogger: segmentAssignmentLogger)
 ```
 
 ## Philosophy