Add git cvsexportcommit page (#9736)

pages/common/git-cvsexportcommit.md

@@ -0,0 +1,8 @@
+# git cvsexportcommit
+
+> Export a single `Git` commit to a CVS checkout.
+> More information: <https://git-scm.com/docs/git-cvsexportcommit>.
+
+- Merge a specific patch into CVS:
+
+`git cvsexportcommit -v -c -w {{path/to/project_cvs_checkout}} {{commit_sha1}}`