fix: update readme (#277)

Author: yamal-alm

README.md

@@ -2037,13 +2037,17 @@ Tells the native app to start the push notification subscription flow. The app
 first verifies that notifications permission is granted; if so, it starts the
 corresponding SDK and executes the push subscription through it.
 
+Only available in Mein O2 and Mein Blau.
+
 ```ts
 subscribeToPushNotifications: () => Promise<void>;
 ```
 
 #### Error cases
 
 -   `401`: Push notifications permission is not granted
+-   `405`: Feature not supported in current brand (only available in Mein Blau
+    and Mein O2)
 -   `500`: Any other error that prevented the operation from completing
 
 ### unsubscribeFromPushNotifications
@@ -2053,12 +2057,16 @@ subscribeToPushNotifications: () => Promise<void>;
 Tells the native app to unsubscribe from pushes through the corresponding SDK.
 No permission is required.
 
+Only available in Mein O2 and Mein Blau.
+
 ```ts
 unsubscribeFromPushNotifications: () => Promise<void>;
 ```
 
 #### Error cases
 
+-   `405`: Feature not supported in current brand (only available in Mein Blau
+    and Mein O2)
 -   `500`: Any other error that prevented the operation from completing
 
 ## Error handling

src/push-notifications.ts

@@ -5,8 +5,11 @@ import {postMessageToNativeApp} from './post-message';
  * The native app verifies the notifications permission first; if granted, it
  * starts the corresponding SDK and executes the push subscription.
  *
+ * Only available in Mein O2 and Mein Blau.
+ *
  * Error cases:
  * - 401: Push notifications permission is not granted
+ * - 405: Feature not supported in current brand (only available in Mein Blau and Mein O2)
  * - 500: Any other error that prevented the operation from completing
  */
 export const subscribeToPushNotifications = (): Promise<void> =>
@@ -16,7 +19,10 @@ export const subscribeToPushNotifications = (): Promise<void> =>
  * Tells the native app to unsubscribe from pushes through the corresponding SDK.
  * No permission is required.
  *
+ * Only available in Mein O2 and Mein Blau.
+ *
  * Error cases:
+ * - 405: Feature not supported in current brand (only available in Mein Blau and Mein O2)
  * - 500: Any other error that prevented the operation from completing
  */
 export const unsubscribeFromPushNotifications = (): Promise<void> =>