Update License and other files

Author: jubarbot-cisco

CONTRIBUTORS.md

@@ -0,0 +1,10 @@
+# Contributors
+
+CONTRIBUTORS file should only contain list of copyright holder (i.e. employers of
+maintainers). All files that support comments should include standard header for
+the project. AGNTCY uses the following file header:
+
+    Copyright AGNTCY Contributors (https://github.com/agntcy)
+    SPDX-License-Identifier: Apache-2.0
+
+1. Cisco Systems Inc.

LICENSE

@@ -1,4 +1,5 @@
-Apache License
+
+                                 Apache License
                            Version 2.0, January 2004
                         http://www.apache.org/licenses/
 
@@ -174,28 +175,3 @@ Apache License
       of your accepting any such warranty or additional liability.
 
    END OF TERMS AND CONDITIONS
-
-   APPENDIX: How to apply the Apache License to your work.
-
-      To apply the Apache License to your work, attach the following
-      boilerplate notice, with the fields enclosed by brackets "[]"
-      replaced with your own identifying information. (Don't include
-      the brackets!)  The text should be enclosed in the appropriate
-      comment syntax for the file format. We also recommend that a
-      file or class name and description of purpose be included on the
-      same "printed page" as the copyright notice for easier
-      identification within third-party archives.
-
-   Copyright 2025, Cisco and/or its affiliates.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.

README.md

@@ -40,24 +40,12 @@ learn, inspire, and create. Any contributions you make are **greatly
 appreciated**. For detailed contributing guidelines, please see
 [CONTRIBUTING.md](docs/CONTRIBUTING.md)
 
-## Copyright Notice and License
+## Copyright Notice
 
 [Copyright Notice and License](./LICENSE)
 
-Copyright (c) 2025 Cisco and/or its affiliates.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-
+Distributed under Apache 2.0 License. See LICENSE for more information.
+Copyright AGNTCY Contributors (https://github.com/agntcy)
 
 ## Acknowledgements
 

docs/CONTRIBUTING.md

@@ -37,6 +37,28 @@ We expect new pull requests to include tests for any affected behavior, and, as
 we follow semantic versioning, we may reserve breaking changes until the next
 major version release.
 
+## Developer’s Certificate of Origin
+
+To improve tracking of who did what, we have introduced a “sign-off” procedure.
+The sign-off is a line at the end of the explanation for the commit, which
+certifies that you wrote it or otherwise have the right to pass it on as open
+source work. We use the Developer Certificate of Origin (see
+https://developercertificate.org/) for our sign-off procedure. You must include
+a sign-off in the commit message of your pull request for it to be accepted. The
+format for a sign-off is:
+
+```
+Signed-off-by: Random J Developer
+<random@developer.example.org>
+```
+
+You can use the -s when you do a git commit to simplify including a properly
+formatted sign-off in your commits. If you need to add your sign-off to a commit
+you have already made, you will need to amend:
+```
+git commit --amend --signoff
+```
+
 ## Other Ways to Contribute
 
 We welcome anyone that wants to contribute to `acp-spec` to triage and