add some new notes

Author: DingGuodong

functions/git/note.md

@@ -50,6 +50,8 @@ git pull 是git fetch + git merge的组合。git pull是把远程仓库更新到
 ```shell script
 git remote add upstream git://github.com/public/repo.git
 git fetch upstream
+git merge upstream/master
+git push origin master
 ```
 
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