READMEs: add contact and copyright sign to copyright notice

Also only reference year of initial publication.

Author: greenrobot-team

README.md

@@ -166,7 +166,7 @@ ObjectBox supports multiple platforms and languages:
 ## License
 
 ```text
-Copyright 2019-2025 ObjectBox Ltd. All rights reserved.
+Copyright © 2019 ObjectBox Ltd. <https://objectbox.io/>
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

objectbox/README.md

@@ -148,7 +148,7 @@ See the [FAQ](https://docs.objectbox.io/faq) and [Troubleshooting](https://docs.
 ## License
 
 ```text
-Copyright 2019-2025 ObjectBox Ltd. All rights reserved.
+Copyright © 2019 ObjectBox Ltd. <https://objectbox.io/>
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.