contributing: Add section for Eclipse Contributor Agreement

CONTRIBUTING.md

@@ -4,6 +4,7 @@ SPDX-FileCopyrightText: Huawei Inc.
 SPDX-License-Identifier: CC-BY-4.0
 -->
 
+- <a href="#eclipse-contributor-agreement" id="toc-eclipse-contributor-agreement">Eclipse Contributor Agreement</a>
 - <a href="#gitlab-contributions" id="toc-gitlab-contributions">Gitlab Contributions</a>
   - <a href="#overview" id="toc-overview">Overview</a>
   - <a href="#git-setup" id="toc-git-setup">Git setup</a>
@@ -18,6 +19,14 @@ SPDX-License-Identifier: CC-BY-4.0
   - <a href="#overview-1" id="toc-overview-1">Overview</a>
   - <a href="#docs_dco" id="toc-docs_dco">Developer Certificate of Origin</a>
 
+# Eclipse Contributor Agreement
+
+Before your contribution can be accepted by the project team, contributors must electronically sign the \[Eclipse Contributor Agreement (ECA)\](<http://www.eclipse.org/legal/ECA.php>)
+
+Commits that are provided by non-committers must have a Signed-off-by field in the footer indicating that the author is aware of the terms by which the contribution has been provided to the project. The non-committer must additionally have an Eclipse Foundation account and must have a signed Eclipse Contributor Agreement (ECA) on file.
+
+For more information, please see the \[Eclipse Committer Handbook\](<https://www.eclipse.org/projects/handbook/#resources-commit>)
+
 # Gitlab Contributions
 
 ## Overview