Add DCO Documentation and github configurations

Remove code-of-contact as it is provided by spring-projects

.github/dco.yml

@@ -0,0 +1,2 @@
+require:
+  members: false

CONTRIBUTING.adoc

@@ -6,12 +6,6 @@ Spring Cloud Dataflow is released under the Apache 2.0 license. If you would lik
 
 
 
-== Code of Conduct
-This project adheres to the Contributor Covenant link:CODE_OF_CONDUCT.adoc[code of conduct].
-By participating, you are expected to uphold this code. Please report unacceptable behavior to [email protected].
-
-
-
 == Using GitHub Issues
 We use GitHub issues to track bugs and enhancements.
 If you have a general usage question please ask on https://stackoverflow.com[Stack Overflow].
@@ -23,15 +17,14 @@ Ideally, that would include a small sample project that reproduces the problem.
 
 
 == Reporting Security Vulnerabilities
-If you think you have found a security vulnerability in Spring Pulsar please *DO NOT* disclose it publicly until we've had a chance to fix it.
+If you think you have found a security vulnerability in Spring Cloud Data Flow please *DO NOT* disclose it publicly until we've had a chance to fix it.
 Please don't report security vulnerabilities using GitHub issues, instead head over to https://spring.io/security-policy and learn how to disclose them responsibly.
 
 
 
-== Sign the Contributor License Agreement
-Before we accept a non-trivial patch or pull request we will need you to https://cla.pivotal.io/sign/spring[sign the Contributor License Agreement].
-Signing the contributor's agreement does not grant anyone commit rights to the main repository, but it does mean that we can accept your contributions, and you will get an author credit if we do.
-Active contributors might be asked to join the core team, and given the ability to merge pull requests.
+== Developer Certificate of Origin
+All commits must include a **Signed-off-by** trailer at the end of each commit message to indicate that the contributor agrees to the Developer Certificate of Origin.
+For additional details, please refer to the blog post https://spring.io/blog/2025/01/06/hello-dco-goodbye-cla-simplifying-contributions-to-spring[Hello DCO, Goodbye CLA: Simplifying Contributions to Spring].
 
 
 === Code Conventions and Housekeeping