The reason is that the local readme.md is inconsistent with the newly created readme.md when GitHub creates a new repository.
Solution: delete the local readme.md and re-enter git pull -rebase origin master and then git push -u origin master
The reason is that the local readme.md is inconsistent with the newly created readme.md when GitHub creates a new repository.
Solution: delete the local readme.md and re-enter git pull -rebase origin master and then git push -u origin master