[docs] add a code example for listing commits of a MR

Gauvain Pocentek · Gauvain Pocentek · commit 037585cc84cf · 2018-05-10T15:00:29.000+02:00
Fixes python-gitlab#491
diff --git a/docs/gl_objects/mrs.rst b/docs/gl_objects/mrs.rst
@@ -82,6 +82,10 @@ Cancel a MR when the build succeeds::
     mr.cancel_merge_when_build_succeeds()  # v3
     mr.cancel_merge_when_pipeline_succeeds()  # v4
 
+List commits of a MR::
+
+    commits = mr.commits()
+
 List issues that will close on merge::
 
     mr.closes_issues()
