Add a note that all Pull Requests are tested at GitHub Actions (#775)

diff --git a/content/en/docs/contribution-guidelines/_index.md b/content/en/docs/contribution-guidelines/_index.md
index 59b6899..c02a9fd 100755
--- a/content/en/docs/contribution-guidelines/_index.md
+++ b/content/en/docs/contribution-guidelines/_index.md
@@ -66,6 +66,7 @@
     git push origin your_awesome_patch
     ```
 * Submit a pull request to apache/dubbo and wait for the reply.
+* All pull requests are automatically tested on [GitHub Actions](https://github.com/apache/dubbo/actions) for AMD64 CPU architecture. Please check that all builds are successful! Additionally there are nightly tests set up at [TravisCI](https://travis-ci.com/github/apache/dubbo) to prevent any regressions on ARM64 CPU architecture.
 
 Thanks for contributing!